The exterior finish phase of construction covers the materials and processes used to get the structure weathered in and water tight, including the architectural materials and processes that give each building its distinct characteristics. These materials and processes include the roofing system, moisture protection membranes, flashings, windows, exterior doors, and siding and trim. The discussion will begin with roofing systems.
The roofing system is usually the first exterior system installed on a structure after the framing is completed. This is done to protect the structure from rain, snow, and other harmful or dangerous conditions. Most dimensional and engineered framing material can withstand the effects of the elements for a short period of time while the structure is being completed; still, it is best to get some form of moisture protection on the structure as soon as possible to help limit any degradation that can occur from long exposure.
A roofing system typically consists of a number of different materials and layers including roofing felt, ice and water shield, drip edge, shingles, flashing, and nails. Each of these materials will be covered in detail. Figure 10-1 shows a delivery of roofing materials, including roofing felt, ice and water shield, and shingles.
Figure 10-1: Roofing material delivery.
Roofing felt is usually the first element placed upon the roof in a roofing system. Roofing felt is manufactured by saturating heavy felt with asphalt or coal tar material. The felt comes in 36-inch-wide rolls and is made in several thicknesses designated as 15 lb., 30 lb., and 60 lb. This is the weight of felt that is needed to cover 100 square feet of roof area or what is known as one square. Each 36-inch-wide roll of felt weighs approximately 60 pounds, with the length of the roll getting longer as the weight per pound decreases. A 60-lb. roll of felt is 36 feet long, which means it actually covers 108 square feet, but with the need for lapping each layer, it is usually calculated as covering 100 square feet, with the additional 8 square feet lost as a lap allowance. Correspondingly, a 30-lb. roll of felt is calculated to cover 200 square feet of roof, and a 15 lb. roll covers 400 square feet of roof. Commonly, both 15-lb. and 30-lb. felt are used as underlayment for asphalt roofing shingles; the heavier 60 lb. felt often has a mineral layer on it and is used as a rolled roofing cover in utility construction.
In more recent years, manufacturers have developed synthetic roofing felts. These are usually some form of plastic polymers that are manufactured for that purpose. Often, synthetic underlayment comes in rolls that are traditionally wider and longer than felt, so each roll covers more roof area and is faster to install. They also have the benefit of being stronger and more resilient in high wind areas. Also, some products can be left exposed on the roof before being covered with roofing shingles for a much longer period of time. They are typically more expensive than traditional felts, but they are becoming much more popular because of the other advantages. Estimating roofing felt is a matter of determining the square footage of the sloped roof area and the amount of coverage that each roll provides. A role of 15-lb. felt contains 423 square feet of felt, but when installing the felt, there is a minimum of 2-inch overlap on the edge and 4 inches on the ends. Most estimators assume that one role of 15-lb. felt will cover approximately 400 square feet. A role of 30-lb. felt covers approximately 200 square feet. Roofs that are cut up or have a lot of angles will need additional roofing felt. Synthetic felt is sized a little differently. Rolls are sized in rounded increments, and so the overlap quantity will need to be calculated and subtracted from the total. For example, a 1000-square-foot-role of synthetic felt would still have an overlap requirement. A lapping requirement of 4 inches limits the amount of coverage to 916 square feet.
Ice and Water Shield
Ice and water shield is a self-sticking roofing membrane that is used to protect the structure due to ice dams. An ice dam is caused when the heat from the attic rises through the roof and melts the snow on the roof. The water runs to the end of the roof until it gets to the eaves, where the roof’s edge is cold, which causes the water to freeze again and turn into ice along the edge. The ice can cause the shingle to lift up and to build up thick enough to form a negative slope on the roof. The water then is able to run back into the interior of the structure. The ice and water shield is usually wide enough that it extends several feet back into the roof past the overhang to seal the roof past any areas where leaks will form. The ice and water shield can be used to seal other vulnerable areas of the roof.
Ice and water shield usually comes in rolls three feet wide and in varying lengths, such as 75 feet. Estimating ice and water shield is usually a matter of calculating the total length divided by the length per roll. Figure 10-4 shows ice and water shield installed along the edge of a roof with roofing felt installed above the ice and water shield.
Figure 10-4: Ice and water shield and roofing felt on a roof.
Drip edge is a metal flashing that is placed along the edge of the roof. It forms an overhang that allows the roofing material to extend past the edge of the roof. This forces the water that runs off the edge of the roof out away from the fascia. If the water is allowed to run down the fascia, it can make its way back into the structure and cause rot and other damage. Most professionals recommend installing the drip edge to the roof decking along the eaves of the roof and then installing the ice and water shield and roof felt over the drip edge. The drip edge is installed over the ice and water shield and roofing felt along the gable ends of the roof. Figures 10-5 through 10-7 show examples of drip edge installation.
Figure 10-5: Drip edge installed over roof sheathing.
Figure 10-6: Drip edge along fascia.
Figure 10-7: Drip edge installation.
Asphalt shingles are the most popular type of residential roofing in North America. Asphalt shingles are popular because they are relatively inexpensive when compared to other roofing material types; they are easy to install, they come in a wide range of colors and styles, they are durable, and they have a good life span. They have been widely used as a roofing material since they were invented over 100 years ago. Originally, asphalt shingles were made by impregnating a mat of cotton felt with asphalt resins and coating the shingles with a layer of crushed slate to add protection and durability. Other organic material such as wool, wood pulp, and jute replaced cotton felt due to the high cost in the 1920’s. In the early 1960’s, fiberglass was introduced as material for the mat and is now commonly used in the majority of shingles produced. Fiberglass is more fire resistant than paper and other organic material, and it allows the shingles to be made using less asphalt resin.
Many types of granular surfaces are used to provide protection and color to the shingles. Common minerals include slate, quartz, vitrified brick, and ceramic granules. Many different styles of asphalt shingles have been manufactured over the years. Four major categories of shingles are common today: strip shingles, tab shingles, dimensional shingles, and luxury shingles.
Strip shingles are the original and most basic type of asphalt shingles. They are constructed of a single layer of asphalt impregnated mat. They have been manufactured in a variety of shapes including single tab, hexagon tab, and round tab, but the most common style of strip shingle is the three tab. Figure 10-8 shows an example of a three-tab shingle. The shingle is partially divided into three separate sections. They are typically thinner and lighter in weight than dimensional and luxury shingles and have a shorter life expectancy of 20 to 25 years. Three-tab shingles used to be the most popular style of shingle, but their use has declined in recent years and now are mostly installed by residential contractors building rental properties and economy priced homes. They are also used in replacement situations and for making starter strips and hip and ridge coverings. Figure 10-8 shows an example of a typical three-tab shingle installation.
Figure 10-8: Single layer three-tab shingle with consistent tab spacing.
Figure 10-9: Typical three-tab shingle installation.
Improvements in the manufacturing process and the desire from customers for a more elegant architectural look have led to the development of multi-layer dimensional shingles. Dimensional shingles are also called laminated shingles or architectural shingles. Typically, these types of shingles are two or three layers thick and weigh significantly more than three-tab strip shingles. The layout and pattern of the shingle is three dimensional with multiple thickness layers and varied tab layouts to give the roof more of a pattern of shade and dimension to resemble more traditional roofing materials such as wood shakes.
An additional advantage of dimensional shingles is that they create a roof covering that is more robust and can last longer than strip shingles. These types of shingles can have an expected life span of 30 to 40 years. The additional weight of this type of shingle also contributes to their ability to better withstand damage caused by wind. The additional benefits of these types of shingles have contributed to their significant increase in popularity and have made these types of shingles the most popular style of residential roofing and has helped to contribute to the decline in the use of strip style shingles. Figure 10-10 shows an example of the construction of one type of dimensional shingle. The tabs on the top layer in this example are cut at a slight angle and have varying widths and spacing. The bottom layer is recessed under the top tab layer and gives the shingle a three-dimensional look, as can be seen in Figure 10-11, which shows the effect of the light and shadow from dimensional shingles installed on a roof.
Figure 10-10: Two-layer dimensional style shingle with varied tab spacing.
Figure 10-11: Effect of light and shadow in dimensional shingles.
Luxury shingles are also known as premium or designer shingles. These are asphalt shingles that are made to emulate the look of a traditional slate or wood shake roof. They are multi-layer shingles that have deeper profiles and greater variation in individual tab lengths, shapes, and colors. This style of shingles commands not only a premium price for materials but would also require additional installation labor.
Figure 10-12: Sample luxury shingle styles.
Installing asphalt shingles
Several factors need to be taken into consideration when installing asphalt shingles. These factors include the shape and size of the shingles, the exposure amount, the starter course, valleys flashing, and valley shingles, hip and ridge shingles, and flashing and roof vents. Each of these will be discussed in turn.
Shape, Size, and Exposure of the Shingles
While there can be a wide variation in shingle size, most asphalt shingles are two standard sizes: an English standard that is 12 inches wide by 36 inches long and a metric standard that is 337 millimeters wide (13-1/4 inches) and 1 meter (39-3/8 inches) long. Each size of shingle has a specific amount of the shingle that is left exposed to the elements, which is known as the exposure. Typically, English size shingles have a 5-inch exposure, while a metric standard shingle has a 5 5/8-inch exposure (Figure 10-13).
Figure 10-13: Shingle exposure.
The first horizontal row of shingles on a roof is the starter strip. This is the initial layer of shingles that is laid down that serves as the base for the roof shingles. Traditionally, the starter course was created by either turning the first row of three-tab shingles upside down on the edge of the roof. Another method was to cut half of the width of the three-tab shingle and use it as the starter course. Most shingle manufacturers produce a dedicated starter strip. Purchasing a premade starter strip usually saves money as it is commonly cheaper to purchase the premade item as opposed to creating one from standard shingles. In addition, it takes less labor to install a premade starter shingle than to cut and install one from a standard three-tab shingle. Several types of starter courses are manufactured. The first is made in a strip the size of a standard shingle. Each full shingle has a perforation down the center that allows it to be broken into two 6-1/2″ × 38″ pieces. The starter course has a strip of sealing adhesive that is placed close to the edge of the roof to keep the bottom edge of the shingles down in high wind. Figure 10-14 shows an example of a starter strip that will be split down the middle before installing.
Figure 10-14: Starter strip
A second type of starter strip is shown in Figure 10-15 that comes in roll form that is laid down as a continuous length.
Determine the amount of starter strip along the horizontal edge of the roof that is needed. Then, determine the lineal feet of the starter strip supplied in each bundle or roll and determine the number of bundles or rolls needed. For example, a bundle of starter strips may have 120 lineal feet, while a roll type might have 33 feet. Figure 10-16 shows an example of a starter strip attached along the end of the roof. The starter strip is nailed down along both the horizontal and gable roof edges.
Figure 10-16: Starter strip along the roof edge.
Roof valleys require a layer of flashing protection in addition to the shingle layers. A number of different products can be successfully used as flashing, including sheet metal and membrane flashing.
Sheet Metal Flashing
Some form of sheet metal has been used as valley flashing for centuries. Sheet lead was one of the first metal flashing products but is not commonly used today due to the high cost and the toxicity of lead. Sheet copper is also another traditional flashing material that is still occasionally used. Because of the high cost of copper, its use as flashing is usually limited to high-end construction and historic restorations. More commonly used as metal flashing are galvanized steel or aluminum. The aluminum may be left with the silver tone mill finish, or it may be anodized, which imparts a very hard colored finish to the metal.
Figure 10-17: Preformed W and rolled metal flashing.
The metal flashing can be purchased in a roll of a specific width and length, such as 18 inches wide by 50 feet long. In addition, preformed metal flashing can be used. Preformed metal flashing is typically sold in sizes such as 20 inches wide by 10 feet long. Preformed metal flashing is also called W flashing because of the distinctive W shape that is formed when a small ridge known as a diverter is formed into the metal shape. This helps keep water running down the valley from migrating up the opposing side of the valley where it may get under the shingles lining that side of the valley. Figure 10-18 shows a high definition luxury shingle roof with a preformed brown anodized aluminum W flashing installed in the valleys. It is also important to note that many shingle manufacturers also require a membrane flashing underneath a metal flashing.
Figure 10-18: Luxury shingle roof with anodized aluminum W valley flashing.
Membrane flashing is made of a pliable membrane. One type of membrane flashing is 90# rolled roofing. This is a heavy duty style of roofing felt that has a mineral layer like standard asphalt shingles. It usually comes in roll form, approximately 3 feet wide and 33 feet long that covers 100 square feet or one square. The rolled roofing is formed in the valley and nailed down along the edges. The nails are kept at least 12 inches away from the center of the valley.
A second type of membrane flashing is adhesive back ice and water shield. The ice and water shield is adhered to the center of the valley and shingled over. Estimating ice and water shield is the same as other membrane flashing by estimating the length of the flashing and dividing by the length of the roll. The installation of the ice and water shield is usually installed along the roof edges first, and the membrane valley flashing is installed over the top to facilitate the smooth flow of the water from the valley to the edge of the roof. Figure 10-19 shows a roof with ice and water shield installed along the roof edges and a valley flashing with the remainder of the roof covered with the synthetic roofing felt.
Figure 10-19: Ice and water shield valley flashing.
There are three generally accepted methods of applying shingles in a valley. The three methods are the open, woven, and closed cut valleys.
The open valley is the same as is shown in Figure 10-18. The shingles are installed so that they are cut back from the center of the valley, leaving the metal valley flashing exposed. This is often done in situations such as historic restorations and high end installations because it is significantly costlier than the other two valley shingling methods. The high cost is due to the additional cost of the metal valley flashing and the added labor to carefully cut each shingle along the valley edge to maintain proper open space in the valley. The open valley method has the additional advantage of allowing the water to move more rapidly off of the roof in the event of a storm, which can help to maintain the roof integrity.
Woven valleys are also considered a desirable method of installing roof valleys; however, their use is limited to three-tab style shingles because the additional thickness of laminated shingles and luxury shingles make them difficult to weave into the proper valley. In addition, woven valleys require the roofer to install two or more roof sides simultaneously because the valley must be woven course by individual course as the roofer moves up the roof. This can add to the complexity of installing the roofing, as the roofer has to work on multiple roof slopes concurrently and may have to install additional scaffolding or utilize safety equipment that allows the installer to move to the different roof slopes.
When installing a woven valley, the roofer installs a single course of shingles along the roof. When the valley is reached, the shingle is bent to form into the valley and allowed to extend at least one foot into the opposing roof slope and nailed off to keep the shingle bent into the valley. Next, the same course is laid on the opposing slope and also formed down into the valley and brought up at least 12 inches into the opposing roof slope and nailed down. Each course is formed up the roof weaving the valley shingles together as shown in Figure 10-20.
Closed Cut Valleys
Closed cut valleys are formed by installing a course of shingles on the roof. When the valley is reached, the shingle is formed into the valley and brought up at least 12 inches past the valley on the opposing side of the roof. The shingle is nailed down similar to the shingles in a woven valley. The shingles are continued course by course up the single roof edge with the end of each course extending into the opposing roof. Once the first side of the roof is installed to the peak, the second side is installed. At the valley, a straight line is chalked down the valley a few inches past the center of the valley, and the shingles of the second side are cut at an angle to match the angle of the valley. This is shown in Figure 10-21.
Hip and Ridge
The intersection that forms the peak of the roof where two hip roof planes meet and the top intersection where top roof planes on gable style roofs need to be covered with a finished roofing material to keep the roof watertight. Several types of materials can be used, including metal hip, ridge cap flashing, and hip and ridge type shingles.
Metal Hip and Ridge Flashing
Metal hip and ridge flashing is used frequently on roofing material such as slate, wooden shingles, clay tile, and sheet metal roofing. It is not as common on asphalt shingles, but it is sometimes used to add architectural character and detail to high-end roofing installations as shown in Figure 10-22.
Figure 10-22: Metal ridge cap on luxury asphalt shingle installation.
Metal ridge cap flashing is available in a number of different profiles and materials including sheet copper, anodized aluminum, and galvanized or painted steel. It is also available in many sizes and profiles from basic utilitarian shapes to historic architectural profiles. Figure 10-23 shows some sample metal ridge cap flashing profiles.
Figure 10-23: Sample metal ridge cap profiles.
Estimating metal ridge cap flashing is a matter of determining the length of ridge needed and dividing by the length of the premade ridge cap. Frequently, it is provided in lengths of around 10 feet.
Hip and Ridge Shingles
Asphalt hip and ridge caps are the most common type of ridge caps used on asphalt shingle roofs. They can be bought as a premade cap or made onsite from standard three-tab shingles.
Premade Hip and Ridge Shingles
Most manufacturers of asphalt shingles provide a pre-manufactured option for completing the hip and ridge portions of a roof. Pre-manufactured hip and ridge shingles are usually provided in a box or bundle with a bundle covering a specific amount of lineal feet of roof peak with the required exposure. Figure 10-24 shows an example of premade hip and ridge shingles.
Figure 10-24: Premade hip and ridge shingles.
Site Made Hip and Ridge Shingles
Traditionally, most hip and ridge shingles have been made on site using standard three-tab shingles. To make hip and ridge shingles, a standard three-tab shingle is cut into three separate sections at the individual tabs. This results in three pieces 12 inches wide for an English size shingle and 13 1/8 inch for a metric size shingle. The back part of the cut is tapered slightly back a few degrees so that it is hidden by the exposure of the shingle above it. This is shown in Figure 10-26.
Figure 10-25: Job cut ridge cap.
The lineal feet of coverage that each bundle of three-tab shingles can cover depends upon the type of shingle. English sized shingles typically have 27 shingles in a bundle. Each shingle is cut into three, so one bundle can make 81 ridge shingles. Each shingle would have an exposure of 5 inches for a total of 33′9″. A metric size bundle of shingles has 21 pieces of shingles, but each shingle has a 5 5/8″ exposure, so one bundle can make 63 ridge shingles with an exposure of 5 5/8″ for a total length of 29′6″.
Estimating site-made hip and ridge shingles is a matter of determining how many lineal feet of hip and ridge need to be covered by the number of individual hip and ridge shingles and the number that each bundle can produce. Figure 10-26 shows an example of site made hip and ridge shingles installed.
Figure 10-26: Site made hip and ridge shingles installed.
Miscellaneous Roof Flashings
Valley flashing and metal ridge flashing may not be the only type of flashings needed on a roof installation. These types of flashing could include chimney flashing, wall flashing, step flashing, and mechanical equipment flashings.
Fireplace chimneys can be problem places for completing the roofing on a structure. It is required that the chimneys extend past the slope of the roof by several feet, which often creates a potential place in the roof where water can pond or enter. This is true for both a traditional masonry fireplace chimney and more current wooden framed chimney chases that house prefabricated metal fireplace flues. The type and amount of flashing needed depends greatly upon the exact location of the chimney in relation to the roof and the potential for water to build up behind or around the chimney. In addition, chimneys that have a horizontal face perpendicular to the slope of the roof wider than 30 inches will need a cricket installed behind the chimney to facilitate the water running around the chimney and down the slope of the roof. Figures 10-27 and 10-28 show some potential chimney flashing methods using corrosion metal flashing material.
Figure 10-27: Chimney flashing with cricket.
Figure 10-28: Chimney flashings.
Anytime the slope of a roof contacts a vertical wall, some form of metal flashing is usually needed. If the ridge of the slope is horizontal to the wall plane, then usually a simple bent flashing will be used. Figure 10-29 shows an example where a bent flashing is installed on the wall plane and bent into the slope of the roof between the layers of shingles. The bent wall flashing will later be covered by the house wrap membrane, so any water hitting the wall will run down the house wrap membrane and out to the surface of the roof shingles. Estimating bent wall flashing is simply a matter of determining the horizontal length of the roof top edge and deterring the manufactured length of the bent flashing to find the number of whole piece that will need to be purchased.
Figure 10-29: Bent wall flashing installed along the vertical wall plane.
On wall installations where the slope of the roof is parallel to the plane, step flashing is used to weatherproof the shingle installation. Step flashing is small L shaped pieces of metal. The horizontal portion of the L shape is placed between each course of shingles and the vertical portion of the L is nailed to the wall plane. Each piece of step flashing is used for only a single course and subsequent pieces’ stair step up the wall as shown in Figure 10-30.
Figure 10-30: Step flashing.
Since one piece of step flashing is used with each course of shingles, once piece of step flashing is estimated for the length of shingle exposure along the sloped distance of the roof. For example, if English size shingles were used with an exposure distance of five inches, then one piece of step flashing would be needed of each five inches of sloped roof length. If metric size shingles were used, one piece of step flashing would cover 5 5/8 inches of the sloped roof length.
Mechanical Equipment Flashing
Several types of mechanical equipment are commonly needed to complete roofing installations. Examples of mechanical equipment flashing include plumbing vent flashings and chimney vent flashings.
Code requires plumbing drainage and waste lines to be vented to the atmosphere. Most often, venting is accomplished by extending plumbing vent lines through the roof plane. Where the plumbing lines exit, the roof usually requires some form of plumbing vent boot. Figure 10-31 shows an ABS plumbing vent extending through the roof structure with a flashing boot installed.
Figure 10-31: ABS pipe vent flashing boot.
Many types of gas fire appliances such as furnaces and water heaters require vents that extend through the roof to remove toxic gases due to the combustion process. Often, these appliances are also vented through the roof using metal chimney ductwork. This ductwork usually requires a flashing boot where it extends through the roofing plane as shown in Figure 10-32.
Proper ventilation of the attic space is an important element of the roofing system in any construction. The attic space should be vented to allow a flow of air in an effort to maintain a temperature that is close to the ambient temperature of the outside air. Not allowing the attic to vent properly can cause the attic space to overheat, which can cause issues and adversely affect the lifespan of the roofing system in both the winter and the summer.
In the winter as the temperature in the attic rises, it causes any snow accumulation on the roof to melt and turn into water. The water runs down the slope of the roof until it reaches the eaves which are not getting heat from the attic space. As the water hits the transition between the attic portion and the eave portion of the roof, it refreezes. As this cycle continues, the freezing water builds up along the roof eaves and forms an ice dam. The ice dam can damage the shingles and can even build up to the point that there is a negative slope on the roof edge, which allows water to flow back into the structure. Keeping the attic cool will help to minimize the freeze thaw cycle and keep the snow on the roof until the entire roof plane is closer to a consistent temperature, allowing the water from the melted snow to completely drain off of the roof edge.
In the summer, the heat in the attic space can build up and cause damage to the roof shingles as they become overheated. In addition, the overheated attic can contribute to a loss of energy efficiency as the warm heated air radiates back into the house in the evening, requiring additional air conditioning. The two primary methods of proving for attic ventilation is to install either multiple individual roof vents or a continuous vent along the ridge. Figure 10-33 shows an example on six individual vents close to the ridge on the back side of a roof. These particular types of vents are also known as turtle vents due the shape.
Figure 10-33: Turtle attic vents on the back side of a roof.
The second type of roof vent that is commonly used is a ridge vent. With a ridge vent, the roof sheathing is cut back one inch on each side of the peak of the roof, allowing a two-inch-wide gap at the roof peak. A commercial ridge vent material that is constructed of some type of porous or screen material is attached over the opening at the roof ridge. The ridge shingles are then placed over the ridge vent material in a manner that allows air to flow freely out of the ridge vent (Figure 10-34).
Figure 10-34: Continuous ridge vent.
Calculating ridge vents depends upon the type. Individual vents are simply a count and list item. Ridge vents are calculated by determining the length of the ridge, which has vents installed divided by the length of vent material in each roll.
Two types of nails are commonly used when installing roofing material. The first type is known as cap nails. These are roofing nails that have a large metal or plastic cap at the head to help provide increased surface area to hold down material, such as roofing felt or ice and water shield, as is shown in Figure 10-2. They are frequently manufactured from corrosion resistant material, such as stainless or galvanized steel, and they are typically hand driven. They are sold in boxes or tubs by the pound (Figure 10-35.)
The second type consists of large head roofing nails which are used to attach the asphalt roofing shingles. Typically, the minimum requirement for nailing shingles is for each shingle to have four nails per full size shingle placed, as shown in Figure 10-38. Shingles applied in locations where they are subject to high winds can require six nails per full size shingle. Both the four nail pattern and six nail patterns are shown in Figure 10-38.
Figure 10-37: Four and six nail shingle nailing patterns.
A rough estimate of the nails can be determined by the amount of roofing material purchased. For example, it is recommended that roofing felt be nailed down at eight inch intervals along both edges and the middle. This results in approximately one and one-half nails per square foot of roof area. A roll of #30 roofing felt can cover approximately 200 square feet of roof, therefore, approximately 300 nails are needed per roll of 30 lb. felt. A roll of #15 felt would need 600 nails. Estimating nails for shingles would be similar, but it would depend upon the number of required nails per shingle. Each bundle of standard size shingles contains 27 shingles. Using a four nail pattern would require approximately 108 nails per bundle, and using a six nail pattern would require 162 nails per bundle. Metric sized shingles would require 88 or 132 nails per bundle, based upon a four or six nail per shingle nailing pattern. Most roofing nails would list the approximate number of nails per box or container and can be used to calculate the number of boxes or containers.
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Tezak, S., Low, D. K., & Reeder, A. (2009). Local officials guide for coastal construction: Design considerations, regulatory guidance, and best practices for coastal communities. Retrieved from https://www.fema.gov/media-library-data/20130726-1707- 25045-9020/chapter10.pdf
Toughened glass. (2018, July 24). Retrieved from https://en.wikipedia.org/wiki/Toughened_glass
Tyvek Construction. (2013, April 09). Flash a Window Sill with FlexWrap™ NF | DuPont™ Tyvek®. Retrieved from https://www.youtube.com/watch?v=SHZuzQNiFho
Vandervort, D. (2016, January 6). Aluminum & Steel Siding. Retrieved from https://www.hometips.com/aluminum_steel_ metal_siding.html
Vinyl Siding Institute. (2017, April 18). Vinyl Siding Installation: Soffit Installation (Part 4 of 9). Retrieved from https://www.youtube.com/watch?v=W7Y_qmXEaFM
Weatherization Partners Ltd. (2013, February 15). How to Flash Wall Penetrations. Retrieved from https://www.youtube.com
Window Types and Technologies. (n.d.). Retrieved from https://www.energy.gov/energysaver/window-types
All About Window Materials
This document gives a detailed overview of the types of window materials used in residential construction projects. Windows for residential construction are manufactured in almost an infinite variety of types, styles, shapes, and sizes, using a number of different materials. The construction estimator will need to become familiar with window types, frame materials, methods of construction, and installation.
Table of Contents
One method of classifying a window is by its type of operation. Fixed windows include non-operating and operating windows, which include window types such as casement, double and single hung, and sliding.
Fixed windows cannot be opened to allow circulation of air, but are fixed in place. The primary purpose of these window types is to allow light to enter the space. They can be very large windows or picture windows, which allow large amounts of lights into a space or access to desirable views. They can be smaller windows where there is no need to allow for air circulation, but it is desirable to allow in light. Fixed windows can be square or rectangular but are also manufactured in an almost infinite variety of shapes and sizes. Fixed windows are often combined with operating windows in an installation.
Operating windows have a sash that can be moved in some way to allow the window to open. Typically, these window types are identified by the way they move. The most common operating window types include casement, sliding, single, and double hung windows.
Casement windows operate by using a hinge action on either the right or left side of the window. Very often, these windows have a crank or other mechanism that operates the window and holds it open or closed at a specific angle. These windows are desirable because they allow almost the entire sash portion to open. Figure 10-41 shows a casement window type.
The sash in sliding windows also moves in a horizontal direction, but the sash slides horizontally in a track. These windows are economical because the sliding mechanism is not as complex as other window operating types. In addition, these windows can be made in larger sizes and still operate efficiently and smoothly. When open, one half of a sliding window covers the other half, so the maximum these window types can be opened at a time is half of the window size (Figure 10-42).
Double and Single Hung Windows
Double and single hung windows operate by allowing the sash to move in a vertical direction. A double hung window has two movable sashes. One is over the other, and each sash can move. The top sash slides down, and the bottom sash slides up. Still, the maximum opening size of the window will only be equal to half of the window size as one sash covers the other when open. The advantage of this type of window is that the top sash can be lowered, which makes the opening at the top of the room and allows warm air that has risen to naturally escape out of the window.
With single hung windows, the bottom sash lifts up to cover the top sash. Both of these window types are also a little more complicated in their manufacture in that there is usually some type of lifting mechanism that holds or counterbalances the weight of the sash and keeps the window sash raised (Figure 10-43).
Some installations use multiple individual window units, each in its own space, such as is shown in Figure 10-44, which has a wall of windows consisting of single hung and fixed window units.
Figure 10-44 Wall of individual windows units with each unit in its own space.
CC0 Gregory Butler, Pixabay-Photo 276551
Combination windows are windows that combine multiple windows together in a single unit. The combination unit could be multiple units all of the same type or combinations of several different types, such as is shown in Figure 10-45, which has a single arched top fixed window unit on top of a sliding unit.
Figure 10-45 Combination window unit.
Window Frame Materials
Modern windows are constructed of a number of different materials including wood, metal, vinyl, fiberglass, and composites.
Wood Window Frames
Wood was the first material that window frames were made from and is still used extensively today. Wood is an excellent material to manufacture. Wood is a beautiful material that is warm and inviting. It also is a very good insulator and helps to make these window types energy efficient. On the downside, wood is subject to decay from moisture and termites and must be regularly maintained. Many modern window manufactures combine wood interiors with a metal, fiberglass, or vinyl exterior to make them more durable. Wood windows also are usually costlier than some of the other alternatives.
Vinyl window frames are made from polyvinyl chloride (PVC) with ultraviolet inhibitors to prevent degradation from sunlight. Vinyl has good moisture resistance and does not require painting. Traditionally, vinyl window frames were manufactured in white, but now, most manufacturers supply them in different colors. The vinyl extrusions can be filled with insulation to make them more energy efficient. They provide a good low maintenance value in a window product.
Fiberglass window elements are made by a process known as pultrusion. The fiberglass roving and veil are covered in a fiberglass resin and pulled through a shaped mold, which forms and hardens the fiberglass. Each resulting straight pultrusion is cut to length and formed into window components. Fiberglass windows are considered stronger and more durable than vinyl windows, which allows the windows to be constructed of smaller pieces, allowing more glass and light. Fiberglass windows are typically about 25 percent more than vinyl. Fiberglass is stable and impervious to moisture, water, mold, and rot. It is also very temperature stable. The exteriors can turn chalky white when exposed to sunlight, and keeping them covered with a sunlight resistant product is essential.
Composite Material Windows
Composite windows are the newest entry into the window market. They are made of a composite material that is a combination of wood plastic resin material. Manufacturers claim that they are stronger and more durable than vinyl. The composite material is stable and impervious to moisture, water, mold, and rot.
Once one of the most common window materials, aluminum extrusions, have gone out of favor because aluminum is a high thermal conductor and has very low thermal efficiency. The windows are strong, lightweight, and durable, but now aluminum is paired with another material, such as wood, to be used for the exterior.
Window with Multiple Material Types
Several manufacturers make windows that are a combination of several material types. For example, there are windows where the interiors are made of warm wood, and the exteriors are either covered in or made from weather resistant material. Some combinations include wood windows where the exterior is covered in weather resistant vinyl or composite material. Another type is a window in which a wood interior is bonded to a weather resistant aluminum exterior. This results in windows that can be both beautiful and very weather resistant. These windows are typically more expensive than those made from a single material. Figure 10-48 shows several different combination window types from Andersen windows.
Figure 10-48 Three Andersen window cladding and combination window types.
CC by Andersen Corp. - ND
Traditionally, windows were made from a single layer of glass that was manufactured to a specific thickness. Glass that is 3/32 inches thick is commonly known as single strength glass. Glass that is 1/8-inch-thick is known as double strength glass. Other thickness such as 1/4 inch, 3/8 inch and 1/2 inch are also available. Single layers of glass are a very poor insulator and contribute significantly to the heat loss and gain in a building. In addition to the need for increased energy efficiency and safety, other architectural requirements have led to an increase in options available in window glazing material.
Energy Efficient Glazing
There are many options and techniques that can be used to increase the energy efficiency of window glazing including insulating glass units, gas filled glazing units, heat absorbing tints, low-emissivity (Low-E) coatings, reflective coatings, and spectrally selective coatings. Energy efficient windows can use one or more of these options to increase their energy efficiency.
Insulating Glass Units
Insulating glass units are window glass units made of two or more window units that are hermetically sealed together and used in the window in place of a single piece of glass. The sealed unit traps air within the unit. Non-moving air is a good insulator and does slow down the heat loss and gain through the unit. The elements of a sealed unit include double panes of glass, a spacer filled with a desiccant material, and sealant around the perimeter of the unit as shown in Figure 10-49.
Figure 10-49 Seal glazing thermal unit construction.
Gas Filled Thermal Units
Gas filled thermal units are similar to regular sealed units, however, with gas filled units, the air inside of the unit has been replaced with an inert gas, such as argon or krypton. These gases are denser, and they slow the rate of thermal transfer.
Low-E coatings or metal oxide coatings are microscopically thin metals that are applied to one or more of the surfaces of the glass. The Low-E coating lowers the U factor of the window. Low-E coatings can be designed to allow for low, moderate, or high thermal gain. However, Low-E coating can reduce the visible transmittance of the window.
Reflective coatings are metallic mirror-like substances that are applied to the glass surface. They reflect back the solar radiation. They have a tendency to block more light than heat, but they are used in areas with high heat gain to help reduce air conditioning costs.
Spectrally Reflective Coatings
Spectrally, reflective coatings are Low-E coatings that are designed to block out specific wavelengths of light while allowing others to pass through. These coating types are often used to reflect the infrared heat wavelength while allowing the visible portion of the light to show through.
Safety glazing is required by the building code in many residential situations. For example, windows that meet all of the following requirements are required to have safety glazing:
- Window is greater than nine square feet in area.
- Bottom edge of the window is less than 18 inches above the floor.
- Exposed top edge of the window is greater than 36 inches above the floor.
- There are one or more walking surfaces within 24 inches of the window.
Safety glazing is usually one of three types: tempered glass, laminated glass, and wired glass.
Tempered glass is created through a process of heating the glass in a furnace to around 1,150 degrees Fahrenheit, after which the outer surface of the glass is cooled rapidly while the inside is left to cool slowly. This puts the outer edges of the glass in tension and makes the surface much stronger. The tension in the glass causes the glass to shatter into many small pieces if the glass is damaged. Safety glass is required by the building code to be etched or permanently marked, identifying the type of glass, the manufacture, the ANSI (American National Standard Institute) standard for safety glass and year, The Consumer Products Safety Commission standard for safety glass, and the Safety Glazing Council product approval number. The label and information can be in the form of a logo (Figure 10-50).
Laminated glass is manufactured by sandwiching a layer of polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA) between two or more layers of glass. The inner layer bonds the glass particles together in the case that the glass is shattered and prevents it from breaking into large dangerous pieces. Laminated glass can also help reduce the sound transmission through a glass window.
Wire embedded glass can be used as safety glass. This was one of the first types of safety glass used, and windows with wire glass can still be seen in many buildings.
Polycarbonates are plastics, such as those sold under trade names such as Lexan® and Makrolon®, that can be used as safety glazing material.
Safety Glazing in Coastal Areas
The building code requires windows along coastal areas prone to hurricanes to be able to have high levels of impact due to wind. Depending on the specific location and the wind load requirements for that area, the impact resistance requirement can be quite substantial. The windows are required to pass what are known as a small missile test and a large missile test. In the most stringent areas, the large missile test requires the window to be able to resist the impact of a standard 8-foot 2 × 4 traveling at a rate of 80 feet per second (Figure 10-51)
Figure 10-51 Two-by-four cannon at the NAHB Housing Innovation Center used to test impact resistance of building materials for use in high wind-prone regions.
There may be specific architectural design requirements for the glazing and windows of a building. These architectural requirements may be as small as requiring obscure glass in the widows of bathrooms and other privacy areas. Architectural glass could also include leaded or stained-glass windows and other decorative glass (Figure 10-52).
Figure 10-52 Decorative window glass used to create architectural detail.
(CC by- Louis G. Redstone Residential Historic District (0022)- NC-ND 2.0)
All About Exterior Door Materials
Exterior doors are available in an almost unlimited variety of materials and styles. Regardless of the particular variety, materials, and styles, all exterior doors need to perform some essential functions, including an ability to be opened and closed easily while retaining the ability to securely keep out unwelcome intruders. They also need to be able to keep out elements of the weather including rain, snow, heat, and cold. They need to hold up under the constant deteriorating effects of the weather. In addition, many exterior doors are a primary area of focus for the home and can contribute to the beauty and street appeal of it. There are both advantages and disadvantages to each style and material, which can both contribute and detract from the door’s ability to meet all of its functions.
Table of Contents
Door Construction Types
In spite of the almost unlimited number of door styles, most can be classified into one of three types: flush doors, panel doors, and sash doors. Each of these types will be covered.
Flush Construction Doors
Flush construction doors have a single smooth flat surface. The doors can be constructed of wood and wood veneers, metal, fiberglass, or composite materials.
Wooden Flush Doors
Wooden flush doors can be both hollow core and solid core. Hollow core wooden doors are primarily for interior use, and they do not hold up well under the demands of the weather. In addition, they are not very secure and can be forced. Solid flush core doors usually have a core of either solid wooden blocks or a composition material such as MDF (Medium Density Fiberboard). The faces of the doors are usually constructed of multilayer veneer plywood at least three layers thick. The face veneers can be paint grade material or high-quality veneers. Moldings can be applied to the faces of the doors to add interest and style to the door.
Metal Flush Doors
Metal flush doors are usually made from steel. They can be made entirely from steel or have a steel skin over other cores, such as wood. All steel doors are most used in commercial buildings. Steel doors in a residential setting are usually steel skin over other materials. Often, the door has a wood frame around the outside along with strategically placed wood blocks located where the hinges and locksets are installed. The rest of the door can be filled with high density foam insulation to aid in increasing energy efficiency.
Fiberglass Flush Doors
Fiberglass exterior flush doors have skins of fiberglass material and insulated interior cores. The edges of the door have a frame made of wood or composite materials. The fiberglass can be smooth or textured to look like wood. The doors can be stained to look like wood. Fiberglass holds up well to the demands of the weather and can make for attractive, stable doors.
Figure 10-54 shows the basic construction of a flat panel door. Materials and construction of the door varies by manufacturer.
Figure 10-54 Flush door construction details.
Panel construction doors can be made from wood, fiberglass, or steel. Wood panel doors can come in many different styles and construction methods. Fiberglass and steel panel doors are constructed in a similar fashion to flat panel doors, but they have embossed exteriors that resemble wood frame and panel doors.
Wood Panel Doors
Traditional wood panel doors are constructed of a number of individual wood pieces that are milled and joined together. Figure 10-55 shows an example of the typical construction of a panel door.
Figure 10-55 Six panel raised panel door.
Traditional wooden panel doors can be made in an almost limitless combination of styles, shapes, and sizes. Figure 10-56 shows an exploded view of a typical six panel door. The outside vertical members are called stiles. The horizontal members are known as rails. In addition, rails are named by their location: bottom, lock, mid, top, etc. The bottom rail is typically the widest rail in the door. The lock rail is usually centered at 38 inches above the base of the doors, which is the center location of the door lockset. Intermediate vertical pieces are known as mullions. Changing the shape and location of the various elements results in a different style of door. This is fairly easy to do. Some door manufactures will custom make doors to a client’s specifications. In addition, many local mills and cabinet shops have the ability to make custom size and shape wood panel doors.
Figure 10-57 shows a few possible raised panel style doors. Doors A and B have flat panels. Doors C and D have raised panels with an arch in the top rails and panels. Door C has an elliptical shaped arch, and door D has a center mullion with ogee shaped arches on each side. Door A has a squared edge joinery, and door B has square edge joinery that has a bead molding placed around the perimeter of the outside of the panels. Doors C and D have copper and stick edge joints.
Figure 10-57 Four raised panel door styles.
Fiberglass and Steel Panel Constructed Doors
Figure 10-58 shows a sample fiberglass and steel panel door. They are constructed with a frame covered with a skin of fiberglass or steel attached to a frame made of LVL lumber, composite, or wood. Fiberglass and steel panel doors are available in a wide number of styles, but manufacturing techniques make it difficult to make true custom style doors. Fiberglass and steel panel doors hold up well to the rigors of weather.
Figure 10-58 Sample frame and panel fiberglass or steel door.
Sash doors have one or more glazing units in them. Building codes require that the glazing in doors be constructed of safety glass—usually tempered or laminated glass. In addition, to meet the needs of modern energy requirements, door glazing is usually constructed with insulated glass panels. A wide array of glazing is available from a small single panel to half lite and full lite doors. Figure 10-59 shows several examples of sash doors with one or more glazing panels.
Figure 10-59 Sash door examples.
The glazing in sash doors can be divided up into smaller windows called lites to provide architectural interest and mimic windows styles in older construction when glass was more economical to construct windows of multiple pieces of smaller glass. Modern manufacturing methods allow glazing to be made in large sizes. It is often desirable to make it appear as if the glazing was built up from many smaller lites to give the door a period look.
Door companies provide a number of different options. Four options are true divided lites, surface mounted grids, grids sealed in between the panes of glass, and a combination that utilizes both surface mounted grids and a matching grid in between the panes of glass. Figure 10-60 shows the four examples.
Figure 10-60 Door glazing divided into lites.
True Divided Lites
The glazing in doors with true divided lites is made of individual thermal units divided by wood millwork. This is similar to how window lites were traditionally made. However, traditional window lites were only single panes of glass. Modern true divided lites are made of individual thermal units with double or triple glazing sealed into individual units.
Surface Grid on Both Sides
The glazing on this type of sash door is usually a single large thermal unit. The look of a divided lite is provided either by adhering mutins directly to the exterior surface of the glazing or creating a removal grid work that is placed on top of one, or both sides, of the glass in the single thermal unit. This provides a traditional look while still using energy efficient single glazing units.
Grids Sealed Between Panes of Glass
Another option to provide the appearance of divided lite in sash doors is to install a grid between the layers of glass when the thermal unit is made. Usually, the grid is made from a vinyl or anodized aluminum material and cannot be changed unless the entire thermal unit is replaced. This provides an economical alternative to give the door a period look at a lesser cost than full divided lites. The color of the grid is also usually somewhat limited and cannot be changed in the future (Figure 10-63).
The last option is to combine both surface mounted grids with a grid installed in between the glazing. This gives the look of full divided lites but allows for the increased energy efficiency of a single thermal unit. The exterior grids can be made of any material to match the exterior of the window. The inside grid is usually aluminum or vinyl.
Premium Style Glass Doors
Entry doors are also manufactured in a wide array of styles with premium glazing. This includes doors with stained glass, leaded glass, or etched glass. Modern doors have the glass sealed within a three-layer thermal unit. Layers of safety glass are placed on the outside with the decorative glass placed in the center (Figure 10-65).
Combination Entry Units
Very often, exterior doors are combined with sidelights and transom windows and other decorative elements to give added architectural interest. Sidelights are narrow vertical units that are added to the sides of entry doors. Commonly, sidelights are placed on each side of the door, however, it is also possible to place a single sidelight on either the right or left side of the door. They are used to add emphasis to the entrance of a building. They can also be used to provide additional light in the entryway. Transom windows can be added to a combination door unit. A transom is a narrow horizontal unit that is placed above the door unit. Often, the transom window is the same width as the sidelights. Combination units can be purchased from manufacturers pre built and assembled, or they may be built up from individual parts and pieces that are assembled on the job. Installing built up units would require the estimator have a knowledge of all of the elements that go into the combination unit (Figure 10-66).
Figure 10-66 Combination entry door unit with two sidelights and a transom unit.
Patio doors are often used to provide access to the outdoors from a room or to provide large amounts of light to the room. Patio doors usually have a frame made from any number of standard door materials including wood, aluminum, vinyl, fiberglass, and steel that encases a glass lite to form a single door panel. Patio doors have two or more of these panels, and at least one panel opens to allow access in one of three configurations: sliding, French, or center hinge.
Sliding Patio Doors
Usually, only one panel on sliding patio doors moves by sliding along a track while the other is fixed in place. They are useful in situations where there may be a limited amount of space to open the doors. A number of frame options are usually available including narrow frames or wider frames meant to imitate more traditional doors. Sliding patio doors are also constructed with a wide range of glazing configuration including single lites, true divided lites, divided lites with surface grids, grids sealed between panes of glass, and combination grid units. Figure 10-67 shows a sliding glass door with wood and vinyl construction. Narrow frames allow for large single lite glazing in the door.
Figure 10-68 shows another example of sliding glass doors. This unit has three units. The two outside units are sliding, and the center unit is fixed. Wider stiles and rails give the doors a more traditional look. A custom arch shaped grid gives the doors high architectural interest.
French doors are patio doors that are hinges on each side and open from the center outward. French doors open wider than other patio doors and can let in more fresh air and access. Typically, one panel on a French door is the main operating panel, and the second panel is secured by some form of sliding bolt. The strike plate for the lockset and deadbolt is attached to the edge of the stationary door. Typically, the operating panel closes against an astragal mounted to the secured unit. This configuration may degrade the energy efficiency of the door. French doors may be purchased in an inward opening configuration or an outward opening configuration. Figure 10-69 shows a pair of French doors with a divided lite configuration.
Center Hinged Patio Doors
At first glance, center hinged patio doors look similar to French style doors, however, the difference is that only one panel is hinged and operates. The hinges are attached to the fixed panel, and the door swings from the center. This is an advantage in some situations because the opening door can swing back against the fixed panel, saving some room in tight situations. Figure 10-70 shows a three panel center hinged patio door. The two panels on the left are fixed, and the left panel is operable.
Figure 10-70 Three panel center hinge patio door.
Exterior Door Installation
Most exterior doors are delivered to the job site pre-hung on the jambs with hinges, weather stripping, threshold, and exterior casing installed. This has significantly simplified the installation of these doors and helped to increase the energy efficiency to exterior doors. Most major manufacturers supply their doors pre-assembled and pre-hung. If not, many building suppliers have the capability of assembling pre-hung doors for delivery to their customers. Figure 10-71 shows a view of a pre-hung door.
Figure 10-71 Pre-hung exterior door.
Figure 10-72 shows a close up view of the threshold portion of the pre-hung door and identifies the essential elements.
Figure 10-72 Close-up view of the threshold portion of a pre-hung exterior door.
Pre-hung Door Parts
Pre-hung exterior doors are usually supplied with the door slab, exterior door jamb set, threshold, weather stripping, and door sweep installed. Often, they are also supplied with the brick molding exterior casing attached. However, some suppliers do not supply the exterior brick molding, and it will need to be purchased separately. The estimator will need to determine the method used by the supplier.
Other items may also need to be purchased to complete the door installation including sill pan flashing, drip cap flashing, and self-adhered membrane flashing.
Sill Pan Flashing
The sill flashing can be a pre-manufactured plastic, vinyl, or metal pan. The pan is often purchased in three parts: two end pieces and a center piece that is assembled onsite. This allows the pan to be sized for different door sizes (Figure 10-73).
Figure 10-73 Prefabricated adjustable sill pan
A sill pan can be fabricated from self-adhered flashing tape. Four pieces of self-adhered flashing will be needed. The first piece is placed across the wall in front of the door at the base. Next, bow tie pieces are cut, bent, and placed in each corner. Third, a piece of flashing is placed along the front of the floor and bent down across the front of the door and walls (Figure 10-74).
Figure 10-74 Door pan flashing constructed of four pieces of self-adhered flashing tape.
Figure 10-75 Exterior door installation flashing details.
Drip Cap Flashing
The top of the door should be flashed in a method that integrates the drainage plane of the exterior wall. A drip cap is placed on top of the brick molding exterior casing attached directly to the wall sheathing (Figure 10-76).
Figure 10-76 Drip Cap Flashing Detail.
Self-Adhered Flashing Tape
The top of the house wrap is cut back at a 45-degree angle, folded back, and temporarily taped out of the way. The side self-adhered flashing tape along the vertical sides of the door are placed over the edges of the drip cap, and the top layer of self-adhered flashing tape is placed across the top over top of the side flashing tape and drip cape. The flap of house wrap is folded back down and attached, and the angle cut is taped over to finish the installation. This will allow any water running down the wall to be channeled to the surface of the house wrap where it can drain away (Figure 10-77).
Figure 10-77 Exterior door top flashing details
Garage doors are available in a wide range of materials and styles. Most contemporary residential garage doors are of the overhead sectional type. This means that the door consists of panels that open by sliding up on an overhead track. Figure 10-71 shows the typical construction of an overhead garage door constructed of five horizontal sections. The top section is glazing, and the bottom four are solid panels that allow the door to roll up on the track to open.
Figure 10-78 Typical overhead garage door construction.
By Doordoctor (Own work) [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Common
Common garage door materials include wood, aluminum, steel, fiberglass, and vinyl. They are made in many attractive styles. Some have insulated cores to assist in energy savings, and others are built to withstand high wind loads required in hurricane-prone areas. Figures 10-79 through 10-83 show some examples of garage doors.
Figure 10-79 Two double garage doors. They are wood grain with arched top windows.
CC-By-Alexa Bing https://books.byui.edu/-bCcH
Figure 10-80 Two single garage doors. Craftsman styles with divided lite windows.
Figure 10-81 Four garage doors. Three elliptical topped doors and one tall door.
CC-By-Alexa Bing https://books.byui.edu/-bCcH
Figure 10-82 Four farm style garage doors.
Figure 10-83 Two wood style garage doors.
Residential garage doors are usually manufactured in standard sizes of both single and double wide configurations. Standard sizes include single door widths of eight feet, nine feet, and ten feet. Double door widths come in standard sizes of 12 feet, 14 feet, 16 feet, and 18 feet. The standard residential garage door is seven feet tall, but eight feet is also common for taller vehicles. In addition to standard sizes, garage doors can be manufactured in a wide range of custom sizes.
Garage Door Installation
Manufactured garage doors are shipped with the materials and hardware needed to install the doors. The additional items estimated are framing lumber pieces used to anchor the door track and hardware to the building. In addition, some form of door jamb material will need to be installed. The actual jamb material will depend upon the installation. For example, Figures 10-79 and 10-81 show a garage door in a masonry installation, and one by wood material is installed as jambs against the door. Figures 10-80, 10-82, and 10-83 show wider material jamb with other wooden trim around them. Figure 10-84 shows the support framing for the garage door. Two by fours are installed on each side of the garage door that extends from the floor to the top plate of the wall. One two by four is also installed across the top. In the center of the door opening, a two by eight vertical center support is installed to anchor the door opening torsion spring. Two by six jamb material is installed around the inside of the opening for the door jambs.
Figure 10-84 Garage door support framing.
All About Exterior Siding Materials
A wide range of products are available for completing the exterior finish of a residential structure. Traditional materials include wood siding, which is available in a diverse array of products, horizontal and vertical panel siding, and wood shingle and shake siding. Masonry materials are another type of traditional exterior finish.
In addition to traditional exterior finish materials, numerous manufactured exterior finish products are also available for use for the exterior finish. These materials include hardboard or other manufactured wood or composite wood products, fiber cement products, steel, aluminum, and vinyl siding. There is also a wide range of manufactured masonry materials available including brick and stone veneers. Most manufactured exterior finish products are fabricated to simulate traditional wood and masonry products. Some of these products will be estimated in the exterior finish phase of the estimate and some in the subcontractor phase.
Another element of the exterior finish that is a vital part of the installation regardless of the material used is the installation of the water-resistive barrier (WRB) and the construction of the exterior drainage plane.
Table of Contents
Water-Resistive Barrier and Exterior Drainage Plane
The acronym WRB used in the construction industry stands for either the water-resistive barrier or weather-resistive barrier. While the two terms may appear to be interchangeable in use, they mean two different things. The function of the water-resistive barrier is to provide a barrier to bulk water intrusion into the interior wall assembly of the structure, which can lead to mold, rot, and a host of other problems. While a water-resistive barrier resists the penetration of bulk water, the material is somewhat porous, and shedding bulk water still allows the passage of water vapor. This is to provide an avenue for moisture that makes its way into the interior of the structure to evaporate out and allow the material to dry.
The function of the weather-resistive barrier is not only to limit the intrusion of bulk water penetration, but to limit the passage of water vapor. Other names for weather-resistive barrier include air barrier and vapor barrier. The installation of a weather-resistive barrier is more complex than that of a water-resistive barrier and usually requires the taping and sealing of all joints and penetrations in the barrier to prevent the free passage of air and water vapors. Weather-resistive barriers are most often used as a standard in more restrictive commercial construction, and the water-resistive barrier is used as the standard in residential construction.
Beginning with the release of the 2012 edition of the International Residential Code, the code mandated the installation of water-resistive barriers on residential construction. Section R703.1.1of the 2012 edition of states:
“The exterior wall envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistant barrier behind the exterior veneer as required by Section R703.2 and a means of draining to the exterior water that enters into the assembly. Protection against condensation in the exterior wall assembly shall be provided in accordance with Section R702.2 of this code.”
Section R703.2 describes the minimum water-resistive barrier material as follows:
“One layer of No. 15 asphalt felt, free from holes and breaks and complying with ASTM D226 for Type 1 felt or other approved water-resistive barrier shall be applied over the studs or sheathing of all exterior walls. Such felt or material shall be applied horizontally, with the upper layer lapped over the lower layer not less than 2 inches. Where joints occur, felt shall be lapped not less than 6 inches. The felt or other approved material shall be continuous to the top of the walls and terminated at penetrations and building appendages in a manner to meet the requirements of the wall envelope as described in Section R703.1.”
Installing a functioning water-resistive barrier is an essential element in all contemporary residential construction projects. There are several approved materials for creating a water-resistive barrier.
Water-Resistive Barrier Materials
The standard specified in the IRC for water-resistive barriers is for No. 15 felt, but there are also several other approved alternatives including grade D building paper, plastic house wrap, liquid-applied WRB’s, rigid foam, and ZIP System sheathing.
Number 15 Felt
Traditionally, number 15 felt has been known as 15lb felt because it weighed 15 pounds per 100 square feet or square. Felt was traditionally made from cotton fiber, but modern felt uses other materials and is lighter in weight and is now called number 15. There are two ASTM standards for felt, and the ASTM D226 standard requires felt with a minimum of 11.5 to 12.5 pounds per square. Lower quality ASTM D4869 weighs 8.0 to 9.7 pounds per square and is not approved by code as a water-resistive barrier. Figure 10-86 shows an example of felt used as a WRB.
Figure 10-86 Felt water-resistive barrier.
Grade D Building Paper
Grade D building paper is a type of lightweight weather-resistive material. Kraft paper is saturated with tar to form a lightweight weather-resistant barrier. Code requires two layers of grade D building paper to meet the WRB requirements. It is often used for a second backing layer underneath stucco or other masonry materials as code does also require two WSB layers under these products. Figure 10-86 shows an example of a second layer of grade D building paper over plastic house wrap and underneath metal lathe in preparation for installing stucco.
Figure 10-87 Grade D building paper as a second layer of WRB in preparation for installing stucco.
Plastic House Wrap
There are many different brands and styles of plastic water-resistive barriers. Most are manufactured from a type of plastic called polyolefin. Several different manufacturing processes are involved in the main types being woven and non-woven, perforated and non-perforated. Each has its own desirable characteristics and cost point. They have become the most common form of water-resistive barrier. Popular brands include Tyvek, Typar, Weathermate, Weathermate Plus, Barricade, and R-Wrap. House wrap typically does a good job of shedding bulk water intrusion while still allowing water vapor to diffuse from the inside of the structure assembly.
House wrap typically comes in rolls nine feet wide, which allows for a single non-lapped layer in typical one-story exterior walls. Some plastic house wraps have a crinkled texture to aid in the draining of water. Figure 10-89 shows an example of a house wrap installation.
Figure 10-88 Plastic house wrap installation.
Liquid-Applied Water-Resistive Barriers
Liquid-applied water-resistive barrier is a material that is directly applied to the sheathing in liquid form. The material can be applied by spraying, rolling, or brushing. It is typically more expensive than some of the other alternatives but provides a very high-quality water-resistive barrier. Figure 10-90 shows a commercial building. The seams of the GlasRoc fiberglass siding have been taped in preparation for applying a liquid vapor barrier.
Figure 10-89 Seams and fasteners heads have been sealed in preparation for applying a liquid-applied water-resistive barrier material.
Figure 10-90 Dark blue liquid-applied water-resistive barrier applied over GlasRoc sheathing.
Courtesy of Nate Allen
Rigid Foam Water-Resistive Barrier
Rigid foam can be used as a water-resistive barrier. The foam must pass a stringent test for sun exposure and water penetration. In addition, specific details of installation must be observed including taping seams and details of window flashing and caulking. Not all brands of rigid foams have been approved for installation. Figure 10-91 shows an example of foam being applied over sheathing as a weather-resistive barrier.
Figure 10-91 Foam water-resistive barrier.
CC-By-Housing Innovation Alliance-NC-SA
ZIP System Water-Resistive Barrier
ZIP System water-resistive barrier is a commercial system composed of two parts: a plywood sheathing coated with a water-resistive material that resists the penetration of bulk water while still being vapor permeable and sealing tape that is applied to the joints to seal them and make them both water and vapor resistant. Figure 10-92 shows a model home with ZIP System sheathing being prepared for testing at the NAHB Housing Innovation Center. Tape still needs to be applied to the joints.
Figure 10-92 ZIP System sheathing applied to model home in preparation for testing.
Flashing membranes are commonly used to seal around window and door openings to help keep out water and other moistures. They have been available since the 1990’s and are an outgrowth of the ice and water shield membranes used in roofing. Traditional techniques do not work well with many contemporary window and door installations. In addition, the development of some contemporary building products and methods of developing more energy efficient buildings initially resulted in other issues related to moisture intrusion and the inability of air tight structures to dry out when moisture would get into the structural assembly.
Flashing membranes are available in a variety of sizes from 4 inches to 18 inches wide. They are also available in a variety of materials, some of which are more suited for installation over different substrates and situations. Most flashing membranes are made from a rubberized asphalt core with a facing of either foil or reinforced polyethylene. The foil-faced flashing can be rated for a longer exposure in the sunlight before being covered. Many plastics faced foil can break down with extended exposure to sunlight. Manufacturers recommend that these be covered with 30 days of installation.
Most flashings are made from either modified bitumen or butyl rubber. Butyl is more expensive but adheres better in the cold and bonds better to a wider range of substrates. Some are manufactured to be very flexible, so it can be formed around sharp corners.
Care should be taken when installing flashing membranes. Most flashings adhere better in warmer temperatures. Installation at temperatures below 50 degrees can compromise the bond. Most flashing should be adhered by pressing with a roller rather than just hand pressure alone. Some materials such as masonry and OSB should be primed before applying flashing membranes. The flashing membrane should be installed on clean substrates before the WRB has a chance to collect dirt and grime. Flashing installation should not rely on the adhesive only. It should be installed in shingle fashion so that higher flashings drain into lower flashings. This keeps the water draining away from the building and integrated into the building’s drainage plane.
House Wrap Tape
Manufacturers also use tape designed to seal the seams of water-resistant barriers. The tape is applied to both horizontal and vertical seams and cuts in the flashing. Care should be observed to install the tape on clean, dry surfaces. The tape should be pressed firmly in place with a J-Roller as it is installed. Figure 10-95 shows an example of a house wrap tape installation.
Figure 10-95 House wrap tape applied to seams in house wrap installation.
Integrated Drainage Plane
The integrated drainage plane is how the water-resistive barrier, self-adhered window, door flashing, and other flashing material is integrated into a complete system. It prevents water from entering into the wall assembly and allows it to drain away from the structure.
One author has suggested that the standard for both water and weather-resistive barrier installation should be as follows:
“The WRB must be properly installed so as to maintain continuity of the barrier. This requires the WRB to be properly integrated with flashings, wall openings, and all adjacent enclosure assemblies, and to be sufficiently overlapped, correctly shingled, and properly sealed or taped at exposed laps (horizontal and/or vertical, depending on its intended purpose), as barrier discontinuities result in potential entry points for water (and air) to migrate into the building (1).”
Details in the installation of these materials and systems are important to creating a functioning, integrated drainage plane. Figure 10-96 shows an example of two window flashings. Flashing material has been installed around the material with little thought about how it will integrate with the WRB and the drainage plane of the building. The completed window will obviously be subjected to moisture as is evident by the beginning of rot and mold visible in the upper left-hand corner of the photograph. The window on the left has flashing that is fully integrated into the drainage plane and WRB. The flashing is tight and installed in shingle fashion to allow water to drain up and away to the surface. All joints and cuts have been taped and sealed.
Figure 10-96 Details of two window flashing installations. The window on the right has been installed with little regard to integrating it with the drainage plane of the building. The window on the left is properly flashed and integrated into the drainage plane.
Figure 10-97 shows examples of exterior door flashings. The door on the right is installed without any drip cap or flashing. Above the door is a flat two-story wall that will collect rainwater and other moisture that will run down the wall. Some of the excess water will find its way underneath the siding and into the door assembly as it hits the top of the door frame. The door on the left has a drip cap and flashing both above the door and on the sides. It is integrated with the WRB to bring the collected water to the surface where it can drain away. The slits in the WRB above the door will need to be taped to keep water from getting underneath the barrier.
Figure 10-97 Details of two door flashing. The door on the right has no drip cap and flashing and nothing to prevent water running down the wall from entering into the assembly. The door on the left has more complete flashing details.
Figure 10-98 shows an example of flashing details of the siding electrical mounting block. The box on the right is attached directly to the WRB surface. Any water running down the wall will make its way into the electrical outlet and interior wall assembly. The flashing on the left uses a small piece of flashing tape to channel water to the surface of the WRB and to drain away.
Figure 10-98 Electrical mounting block flashing detail.
Failure to develop a fully integrated drainage plane can result in significant damage to a structure. Figure 10-99 shows an example of a house. The building was built without a water-resistive barrier. A few years after construction, a deck was added to the build. The builder removed the vinyl siding and made no provisions for draining away the water. The snow built up on the surface and drained into the interior structure. This resulted in significant structural and cosmetic damage within the space of a few years. Extensive repair had to be undertaken.
Figure 10-99 Installation of deck without any WRB or integrated drainage plane resulted in significant structural and cosmetic damage to this structure.
Courtesy: Clark Blaylock
Steel, Aluminum, and Vinyl Siding
Exterior siding products made of steel, aluminum, and vinyl are some of the most common exterior wall finishes used. The material and installation cost of these products tends to be lower than wood, stucco, masonry, or other manufactured wood and masonry products. This is one of the reasons for their popularity. In addition to their lower cost, they have a proven track record of providing a long-lasting, durable exterior finish surface that requires little upkeep and maintenance. Most are manufactured to resemble traditional wood siding products and provide a good value for the cost-conscious consumer.
Steel, aluminum, and vinyl siding are very similar in their look and installation methods. Each of these products have their advantages and disadvantages.
Steel Siding Characteristics
Steel siding is made by extruding steel panels and coating them with a baked on enamel finish. It is available in a wide range of colors and textures that are manufactured to mimic wood siding products. It has the advantage of being the strongest and most durable of these siding products. It holds up well in areas where it is subject to high wind and possible damage to hail. The finish can get scratched, which can lead to rust and other damage. It is also the most expensive of the options to purchase and install. Usually, it requires some specialized equipment to cut and install. It requires little maintenance, and when maintenance is needed, it can be repainted to both improve appearance and increase longevity.
Aluminum Siding Characteristics
Aluminum siding is made by extruding metal panels and coating the panels with baked on enamel finish. It is very durable; it will not rot, rust, burn, or become subject to termite damage. However, it can be damaged by wind and hail. It is available in a wider range of colors and textures than steel siding. It can be repainted to maintain its look and increase longevity. The cost of aluminum siding is between the more expensive steel and less expensive vinyl siding.
Vinyl Siding Characteristics
Vinyl siding is the most popular of the siding products. It is manufactured in the widest range of colors and styles. It is also manufactured in different grades of quality and thickness, which also affects the look and longevity. Thinner and less expensive siding can have a life expectancy of 10 to 15 years, while thick and more expensive vinyl can last up to 40 years. It has good resistance to wind and hail and requires little upkeep, but it cannot be repainted to improve look and lifespan.
The most common length standards for steel, aluminum, and vinyl siding are 12 feet and 12 feet 6 inches, but they are available in longer lengths, such as 16 feet 8 inches, 20 feet, and 25 feet. Most are manufactured in several thicknesses with the thicker grades being considered a costlier premium grade. They are also available in several widths depending on the style from 7 inches to 12 inches wide.
Steel, Aluminum, and Vinyl Siding Styles
While styles and variations may not be available with some siding material, there is a wide range of available styles within each category of siding. The available styles can be subdivided into three major types: horizontal, vertical, and shingle style of siding. Within each of these types, there are also several different styles.
Horizontal siding is manufactured to closely resemble traditional wood siding styles, which would include beveled clapboard siding and Dutch lap siding. Figure 10-100 shows examples of a number of horizontal siding profiles.
Figure 10-100 Horizontal siding profiles.
Vertical siding is also manufactured to resemble traditional wood vertical wood siding styles, including board and batten and drop channel siding (Figure 10-101).
Figure 10-101 Vertical siding styles.
Shake and Shingle Siding
Shake and shingle siding is manufactured to resemble traditional wood shingle and shake siding. Traditional shingle siding is made to resemble sawn cedar shingle; whereas, shake siding is made to resemble hand split shake roofing shingles. In addition, shingle siding is also made to resemble sculptured Victorian style shingles, such as scalloped bottom shingles (Figure 10-102).
Figure 10-102 Shake shingle style siding.
The technique for installing aluminum, steel, and vinyl siding is similar for all material. The soffit and fascia system is usually installed prior to the siding installation and will be covered in a later portion of this chapter. Horizontal siding is installed from the bottom of the wall working towards the top. Vertical siding can be installed from the left side working towards the right side or vice versa. Aluminum, steel, and vinyl products have a high coefficient of thermal expansion and expand when exposed to the heat of the summer sun and contract during the cold of winter. This expansion and contraction can be significant, and siding must be installed in a fashion that will allow it to expand and contract with the changes in the temperature. Several features are included in these products to accommodate this expansion and contraction. The first of these features is pre-punched nailing slots along the nailing hem. The siding is attached to the structure with either large headed galvanized or stainless roofing nails or staples. The fasteners are placed in the center of the slot and left with a small gap between the head of the nail or staple and the siding so that the siding can move freely back and forth as it expands and contracts without unsightly buckling (Figure 10-103).
Figure 10-103 Siding nails are placed in the center of the slot in the nailing hem and stand proud of the surface 1/32″.
Because it often becomes necessary to seam two or more pieces along a course, the nailing hem and locking channel of the siding is cut back a short distance, and the rest of the siding overlaps by at least one inch (Figure 10-104).
Figure 10-104 Siding lap joint details.
Trim and accessory pieces are used in the installation to finish cutting edges and anchor the siding. The trim pieces are also designed to allow the siding to expand and contract and provide a space allowing siding to move without buckling (figure 10-105).
Figure 10-105 One quarter-inch gap is left for siding to expand.
The trim and accessory pieces are usually the first siding elements to be installed.
Aluminum, steel, and vinyl siding requires specific trim and accessory items as part of their installation. Some of the standard trim pieces are starter strip, outside corner posts, J channel, utility trim, dual utility trim, round inside corner post, angled inside corner post, T channel, F channel, and other pieces. Figure 10-106 shows the profiles of these trim pieces. The application and use of each of these trim pieces will be discussed.
Figure 10-106 Siding trim profiles.
Outside Corner Post
The outside corner posts are usually the first siding pieces to be installed. They are marked and carefully plumbed as they are installed on each outside corner to insure a straight installation. The corner posts are installed to the base of the soffit and extend downward one quarter of an inch below the base of the wall. Nails are placed in the top of the highest slots on each side, and the post hangs from those nails. The rest of the nails are centered in the slots. Corner posts come in standard lengths of 10 feet, but other lengths up to 20 feet are available. Several widths and styles are also available from three inches wide up to seven inches wide (Figure 10-106).
Inside Corner Post
Inside corner posts are installed at the same time as the outside corner posts. The installation would also be the same including making sure the trim is installed true and straight. The length would be the same as the length of the outside corner posts (Figure 10-107).
Figure 10-107 Inside corner post installation.
Starter strip is a formed piece of metal or vinyl that is used at the base of a siding installation to provide a straight and level beginning for the installation and to attach the base of the siding to the structure. Starter strip is manufactured in aluminum, galvanized metal, and vinyl. It comes in lengths from 10 feet to 12½ feet. To install the starter strip, measure up from the bottom of the wall a distance equal to the width of the starter strip minus a small amount the siding that should overlap the foundation below, for example, a quarter of an inch. Mark and chalk a level line. The starter strip is attached with galvanized roofing nails or staples even with the level line. Hold the started strip back from the nailing hem of the corner posts and carefully line the top of each piece with the level line fastening with roofing nails or staples (Figure 10-108).
Figure 10-108 Corner post and starter strip installation.
J channel can be used for multiple applications during the installation of the siding to trim and anchor the cut edges of the siding panels. Categories of applications include J channel at the top of wall installations, J channel door and window installation, J channel inside corner and vertical edge installation, and base and other horizontal installations.
J channel top of wall installation
It is used at the top of the installation where the wall siding meets the soffit material. This includes the soffit along the raked angle of gable ends, the edges where the siding meets the boxed gable ends, and the horizontal lengths of soffit. Figure 10-109 shows an example of these three wall top installations.
Figure 10-109 Wall top J channel installations.
J channel door and window installation
J channel is also used around window and door installations. Typically, the four edges of the windows have a J channel installed around them, and the top and both sides of the door exterior brick molding have a J channel installed. There may be some installations where the J channel is also installed at the bottom edge of the door when siding is below the door. Figure 10-110 shows the installation of the brick molding around the door exterior brick molding. When calculating the quantity of brick molding around the door brick molding, additional lengths of J channel should be estimated. The brick molding is typically several inches wide, and the J channel overlaps where horizontal and vertical J channel overlaps. The estimated length of the J channel at the top of the door should be the width of the door plus two times the brick molding width and two times the J channel width. The vertical brick molding should include the height of the door plus the brick molding and J channel width.
Figure 10-110 Installation of J channel around door exterior brick molding.
The installation of the J channel is typically around the four sides of the window. Double the width of the J channel should be added to each length of J channel calculated to account for corner overlap (Figure 10-111).
Figure 10-111 Widow J channel is installed around the four sides of the window opening.
J channel inside corner and vertical edge installation
In addition to standard inside corner post installation, which has been previously discussed, J channel can be used to install siding on inside corners and other vertical edge installations. There are two common methods for using J channel to create inside corners. The first is to use two pieces of J channel to form the corner. The second is to use one length of J channel plus one piece of 90 degree formed trim coil stock.
The two-piece J channel uses two pieces of vertical J channel installed in the corner, one on each side of the corner. The length of the J channel needed is double the length of the corner (Figure 10-112).
Figure 10-112 Two-piece J channel corner installation.
The second J channel corner installation is a four step process. First one piece of formed corner coil stock in the angle. Siding is installed on one wall first, then a piece of J channel is installed on the other wall tight against the face of the siding on the opposing walls. The siding on the second wall is then installed (Figure 10-113).
Figure 10-113 One J channel inside corner installation.
J channel can be used to trim other vertical edges when the siding meets another material such as stucco, brick, or synthetic masonry product. Figure 10-114 shows an example of a vertical J channel installed along an edge where stucco and rock will be installed. The same figure also shows some examples of other miscellaneous installations of J channel. The small roof protecting the gas meter and the penetration of the main gas line is also trimmed out with J channel.
Base and other horizontal installations
Most horizontal installations of siding begin with a starter strip, however, there are some applications where starter strip cannot be used. Often, J channel is substituted. For example, when brick or other masonry that is thicker than the siding is used as a wainscot at the base of the wall, the siding cannot hook underneath the starter strip without leaving an unsightly gap at the base. In addition, the base of the siding is often cut off so that the coursing of the siding remains even with full height siding installation that begins at the base of the wall with a starter strip. Figure 10-115 shows an example of siding installed on top of synthetic masonry wainscot.
Figure 10-115 J channel installed at the base of siding installed on top of a masonry wainscot.
Another application for installing J channel at the base of a siding installation is at the base of siding that is installed on a wall over an adjoining roof. For example, Figure 10-116 shows siding installed on a small wall above an adjoining garage roof. The rake angle of the garage roof requires the base of each siding course to be cut at an angle and the angled cut placed in J channel.
Another application for horizontal J channel is at the base of siding where the siding installation changes from horizontal to vertical style of siding. Figure 10-117 shows an example of this type of installation.
The application of J channel in an installation can vary widely from project to project and can be subject to design requirements of the projects, such as for decorative trim items. In addition, the installation can be subject to installed preferences and techniques, some of which can be subject to use of utility or double utility trim on the projects.
Utility and Dual Utility Trim
Utility trim and dual utility trim are often used in conjunction with J channel during installation to anchor and finish edges, but it can also be used by themselves as pieces of installation trim to serve the same purpose. Figure 10-118 shows a comparison between standard J channel, utility trim, and dual utility trim profiles. The shapes of both are similar in that they have an overall J profile, however, utility trim is narrower, and the end of the J is bent to create a hook to catch a tab that is punched along the horizontal edge of the siding that has been cut. Dual utility trim is similar except that it has two hooked edges that allow for a more universal application.
Figure 10-118 Comparison between J channel, utility trim, and dual utility trim profiles.
The installation of horizontal siding begins at the base, usually with a starter strip, and proceeds vertically up the wall in even increments based upon the designed course spacing of the siding. For example, 4-inch double bevel siding would have a calculated course spacing of 8 vertical inches of wall height. Correspondingly, 5-inch double bevel siding would have a course spacing of 10 inches. At the top of the installation, the wall siding meets the underside of the soffit overhang. The actual distance of the height of the wall siding installation can vary based upon variables such as the floor system thickness, designed wall height, roof slope, and roof overhang. The height of a siding installation with a standard 8-foot wall height can vary based upon the slope and overhang of the roof. Figure 10-119 shows an example of the effect of roof slope and overhang in the siding installation height. The roof on the left has a 4-inch slope and a 6-inch overhang with a siding height of 7 feet, 11 inches. The roof on the right has an 8-inch slope and a 24-inch overhang with a siding height of 6 feet, 9 inches.
Figure 10-119 Roof slope and overhang changes the height of the siding installation.
The change in wall siding height also changes where the top of the siding will be cut to meet the underside of the roof soffit. The example on the left shows how the siding is cut near the top of the bevel, and the example on the right shows how the siding is cut in the center of the portion of the siding flat face. Utility trim or dual utility trim is used to finish and anchor the top of the cut siding. Figure 10-120 shows an example of cutting off the nailing hem at each of the locations described in the Figure 10-119 example.
Figure 10-120 Nailing hem trimmed off of siding to be installed at the top of the wall.
A tool known as a snap-lock punch will be used to punch a row of tabs across the top of the siding edge. The punched tabs will be hooked into the J channel, which is what holds the cut siding piece in place without the nailing hem that has been removed (Figure 10-121).
Figure 10-121 Snap-lock punch is used to punch locking tabs into cut siding edge.
J channel by itself cannot be used instead of utility trim to hold the cut siding in place because there is nothing to hold the locking tabs in place (Figure 10-122).
Figure 10-122 J channel alone cannot hold cut siding in place.
Either utility trim or dual utility trim is used inside of the J channel to hold the cut siding in place. Utility trim is used when the siding is cut at the top of the bevel. Dual utility trim can be used both for siding that is cut at the top of the bevel and siding that is cut on the flat face of the siding.
Figure 10-123 Utility trim inside of J channel to anchor cut siding in place.
Dual utility trim is also used inside of the J channel to hold the cut siding in place. Dual utility trim can be used both for siding that is cut to the back of the bevel or for siding that is cut into the siding face. The use of dual utility trim has a more universal application as it can be used wherever the installation requires the siding to be cut, but the cost is significantly higher than for utility trim (Figure 10-124).
Figure 10-124 Dual utility trim used inside of J channel to anchor cut siding in place.
While J channel cannot be used in this application without the addition of utility or dual utility trim, both utility and dual utility trim can be used without J channel. This practice is very common in the industry, and the choice to include J channel or not is more of a design and installation preference than that of a practical necessity. Figure 10-125 shows utility trim installation with and without J channel.
Figure 10-125 This siding installation uses both J channel and utility trim at the top of the wall installation.
Utility trim and dual utility trim is also used to anchor the siding at the top and the bottom where it is cut around windows and doors. Figure 10-126 shows an example of a siding cut to fit around a window. The cut across the bottom of the window has a row of tabs punched along the edge. Utility trim will be installed under the window to anchor the piece of siding. The utility trim fits inside of the J channel at the bottom of the window. The siding at the top of the window would be cut and punched the same as the siding at the bottom of the window.
Figure 10-126 Siding notched to fit around a window. The siding is punched along the edge for installation in utility trim.
Because there can be some variation in the installation of siding and associated trim pieces, it is essential for the construction estimator to understand all of the elements that go into the installation and to then communicate effectively with the builder or installer to make sure everyone understands exactly how the siding will be installed. Figures 10-127 and 10-128 show exploded views of two walls of siding with the individual siding and trim pieces identified.
Siding Decorative Trim
In addition to standard trim pieces, additional decorative trim pieces are available to add architectural style and interest to the project. These decorative pieces include window and door casings, wide lineal trim, soffit cove, and soffit crown. Typically, these pieces are used instead of typical J channel molding. Figure 10-129 shows some examples of these.
Figure 10-129 Decorative trim profiles.
Door and Window Casing
Door and window casing is trim that resembles J channel, but is wider. Typically, 2½ to 3½ inches wide. This is installed to mimic traditional wood window and door trim, which is typically this wide. It highlights the door and window elements of the exterior of the building. It is supplied in lengths like 12 feet, 6 inches long.
Lineal trim is designed to resemble traditional trim details such as frieze boards, band boards, and water boards at the wall base. Lineal trim has a pock for the siding edge like J channel, but the face is typically wider and is available in dimensions of 3½ inches wide, 5 inches wide, and 7 inches wide. On one side, the lineal is anchored with a finish trim, and the other is attached with a standard nailing hem. Lineal trim is available in lengths like 20 feet long.
Cove and Crown Trim
Cove and crown trim is used at the junction between the top of the wall and the soffit. Again, it is designed to mimic traditional siding details. Cove and crown trim is supplied in lengths like 12 feet, 6 inches long.
Figure 10-130 shows an example of a siding installation detailed with decorative trim pieces including a 7-inch water table at the base. 3½-inch crown trim at the top and 2¼-inch trim around the window and doors.
Figure 10-130 Siding installation with decorative trim details.
There are many other types of siding accessories that are also often part of the siding installation. Some may be essential to the project and others may be for decorative purposes only. These siding accessories include mounting blocks, vents and louvers, shutters, and other decorative elements.
Siding Mounting Blocks
Siding mounting blocks are used to finish the installation around items that penetrate through the siding or mount on the siding. These can include electrical outlets, switches, and light fixtures. Typically, mounting blocks have two parts. The first is a base piece that is firmly attached to the building framing on top of a water-resistive barrier. Where penetrations are made in the WRB, the penetration should be properly shingle flashed and integrated into the barrier. The second piece is a trim piece that snaps onto the base piece. It covers and trims the raw siding edges that are cut around the base piece. This is in essence an integrated J channel for the mounting. Figure 10-31 shows several examples of siding mounting blocks. The top photograph shows four mounting blocks. The top two mounting blocks are for light fixtures, and the bottom two mounting blocks serve as a mounting plate for the street address numbers. The photograph on the bottom left is for a dryer vent; the bottom middle photograph is for an electrical outlet; the bottom right photograph is for a hose bib.
Figure 10-131 Mounting block styles.
Vents and Louvers
Vent and louver trim accessories can serve as both functional and decorative trim items. Many times, vent trim is used as part of the attic ventilation system, or they could serve as simply decorative trim pieces. They are often constructed in a fashion similar to mounting blocks and have an integrated J channel. Other types may be installed that do not have an integrated J channel, and additional J channel will need to be purchased for the installation. Vents and louvers are available in a wide range of styles and sizes. Figure 10-132 shows several examples of vent and louver styles including square, split triangle, triangle, octagon, oval, and round shaped.
Figure 10-132 Six styles of attic vents.
Square: CC0, https://books.byui.edu/-diEL
Double Triangle CC0,
Triangle: CC0, By PaulBr7: https://pixabay.com/en/luxury-home-upscale-architecture-2409577/
Octagon: CC, By:David-D:https://www.flickr.com/photos/david_martin_foto/14299413363
Oval: Public Domain, By Architecture: Reg Summerhayes (1881–1976); this photograph: Hesperian. [Public domain], from Wikimedia Commons
Round: CC0, https://www.pexels.com/photo/architecture-building-business-buy-259098/
Shutters and Other Decorative Elements
Shutters and other decorative elements are used to add architectural interest to the project. These elements are available in an array of sizes and styles. Some suppliers will even make custom styles using a wide range of materials including wood, vinyl, aluminum, and steel. Figures 10-133 shows a house facade that utilizes shutters as a decorative element over both brick and siding.
Figure 10-133 Decorative shutters installed over both vinyl siding and brick.
Other decorative elements include items such as decorative door and window trim, brackets and corbels, gable end accents, column wraps and trim, sunbursts and fans, and door surrounds.
Figure 10-134 Decorative siding elements.
Site Fabricated Aluminum Trim Accessories
Most siding installations will include site fabricated trim accessories. These trim pieces are made from pre-remanufactured aluminum trim coil stock that is cut and bent on the job to meet site specific needs. Aluminum trim coil stock is typically purchased in rolls of 24 inches wide and 50 feet long. It can be purchased in a wide range of colors to either match or compliment the exterior siding material (Figure 10-135).
Some of the fabricated pieces include beam and column surrounds, L angle flashing, and door trim surrounds. The pieces are fabricated on site using a sheet metal siding brake. Siding brakes are available in sizes from 8 feet, 6 inches long to 14 feet, 6 inches long. Even though they are a larger piece of equipment, they are manufactured as lightweight as possible to make it more portable. Some models have support legs that fold down for transport. The roll of trim coil stock is placed in the machine and can be cut and bent using features of the equipment. Additional accessories can be purchased to create other, more complex shapes (Figure 10-136).
Figure 10-136 Sheet metal siding brake.
Figure 10-137 shows the roof support beams for an exterior porch that have been wrapped with a white trim coil facing.
Figure 10-137 Site fabricated trim coil beam wrap.
Figure 10-138 shows the L angle flashing between a brick ledger and the wall siding.
Figure 10-138 Site fabricated L angle flashing between brick ledge and wall siding.
Figure 10-139 shows an example of an exterior door where the jambs and brick molding have been wrapped with trim coil flashing.
Figure 10-139 Site fabricated flashing around door jambs and brick molding.
The roof cornice in residential construction has two principle elements: the horizontal piece known as the Soffit and the vertical, or angled element, known as the fascia. In addition to the soffit and fascia, some cornice styles may have more, or fewer, elements. The roof cornice has two major functions, the first, and most important, is to extend the edge of the roof past the walls of the house to assist in keeping the water cascading off of the roof away from the walls of the house. The second is to provide architectural detail and interest to the structure. One of the primary elements that defines the architectural style of building is the shape of the cornice. There are a myriad of styles and sizes of cornices used in residential construction, however, they are typically categorized into three different types, a boxed cornice, and open cornice, and a closed cornice. Figure 10-140 shows an example of a traditional wood boxed cornice. A 2 × 4 sub fascia board is installed at the end of the rafter tails. A 2 × 4 soffit ledger board is installed along the wall. 2 × 4 soffit lookouts extend from the soffit ledger to the sub fascia. A 1 × 6 wood fascia board is installed on top of the sub fascia and a plywood soffit is attached to the sub fascia, soffit lookouts, and soffit ledger.
Figure 10-140 Traditional wood boxed cornice.
Figure 10-141 shows an example of a sloped roof soffit. The truss tails are cut perpendicular to the slope of the roof. The sub fascia is also installed at an angle with the fascia and soffit installed at the same angle.
Figure 10-141 Slope roof cornice
Figure 10-141 shows an open cornice. The rafter tails have been sculptured to a pattern to add decorative detail to the installation. There is no sub fascia or fascia board. There is blocking, however, that has been installed between each rafter end.
Figure 10-142 Open cornice with sculptured rafter tails.
Figure 10-143 shows an example of a closed cornice. There is no rafter overhang, and the cornice extends only a small amount over the edge of the roof. The edge of the rafters is covered with a wide frieze board. In addition, molding can be added to bring the edge of the roof out past the wall plane a few inches.
Figure 10-143 Closed cornice without any roof overhang.
Steel, Aluminum, and Vinyl Siding Cornice
Steel, aluminum, and vinyl siding soffits are a popular choice for cornice materials. In addition to being used in buildings with steel, aluminum, and vinyl siding, these materials are often used on buildings that have other siding materials such as wood, engineered wood, and fiber cement because of their ease of installation and maintenance free application. Often, the framing support for these materials is not as extensive as for wood fascia and soffit. The actual framing requirements depend upon the siding and trim accessories used. Boxed cornice soffits are typically constructed using separate fascia, soffit, and trim pieces.
Steel, Aluminum, and Vinyl Fascia
Fascia pieces are made from bent or formed L shaped pieces of steel, aluminum, or vinyl. They are manufactured in different standard widths from 4 inches wide to 12 inches wide. In addition, aluminum sheet stock is also commonly site fabricated into fascia material in either standard or custom widths. The L shaped material is commonly hemmed at the top and front edge to increase stiffness and strength. In addition, aluminum and vinyl fascia is often ribbed to add additional strength and stiffness. The fascia material is installed directly on top of the sub fascia with the bottom edge pressed up to the soffit and the top edge tucked under the drip edge. Figure 10-144 shows some examples of soffit materials.
Figure 10-144 Examples of fascia.
Steel, Aluminum, and Vinyl Soffit
Soffit material is available commonly in either steel, aluminum, or vinyl. Several different widths and styles are available. The pattern is commonly formed to resemble grooved wood siding material. The patterns available would include 6-inch-wide single pattern,6-inch-wide double pattern, 5-inch-wide double pattern, 4-inch-wide triple pattern, and 4-inch-wide quad pattern. The total width of each piece of soffit would be multiples of each pattern repeated.
Figure 10-145 A few soffit styles.
In addition to the solid soffit styles shown in Figure 10-145, soffit material is also available vented to allow for attic ventilation. Soffit can be either fully vented where all of the faces have ventilation holes in them or partially vented with some of the faces vented and others not as shown in Figure 10-146.
Figure 10-146 Fully and partially vented soffit material.
Most soffit installations will require additional trim included in the project. Some trim that could be required includes soffit J channel, soffit F channel, soffit H trim, and utility trim. Figure 10-147 shows some examples of these.
Figure 10-147 Examples of soffit trim profiles.
Figure 10-148 shows an example of a boxed cornice application that utilizes three siding elements: fascia, soffit, and F channel. The F channel is attached directly to the wall sheathing. One edge of the soffit is supported by the F channel, and the other is attached to the sub fascia. The fascia is tucked up under the drip edge, and the bottom is supported by attaching it to the sub fascia (Figure 10-148).
Figure 10-148 Boxed cornice installed with F Channel, soffit, and fascia.
Another common method of a boxed cornice installation uses fascia, soffit, and J channel. This installation requires the addition of a ledger strip to attach the J channel to as it is difficult to attach it directly to the wall sheathing.
Figure 10-149 Boxed cornice installed with J channel, soffit, fascia, and ledger strip.
Figure 10-150 shows an example of an angled soffit installation. The soffit is sloped to match the roof slope, and the fascia is installed perpendicular to the soffit. The installation requires fascia, soffit, and J channel.
Figure 10-150 Angle soffit installation with soffit installed perpendicular to the soffit.
H Channel is used to join pieces of siding or soffit material along the cut edge. For example, it is commonly used in forming the soffit where the walls meet at a corner. The soffit material is mitered at the corner where the two sides meet. H channel is placed between the two pieces. Another way of forming the corner is to have the sides meet at perpendicular angles with H channel between the pieces. Both types of soffit corners are shown in Figure 10-151.
Figure 10-151 Soffit corners finished with H channel.
H channel can be formed from two pieces of J channel placed back to back. Figure 10-512 shows a perpendicular porch soffit with J channel placed back to back to form the H channel.
Figure 10-152 Perpendicular soffit with seam formed by back to back J channel.
H channel or back to back J channel can be used where the area to be covered by the soffit is longer than the soffit of siding material, and a seam is needed. Figure 10-153 shows an example of a porch soffit seam formed from back to back J channel.
Figure 10-153 Porch soffit seamed with double J channel
Figure 10-154 shows an example of vertical siding on a tall wall that has been seamed with H channel.
Figure 10-154 Vertical wall siding seamed with H channel.