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The rough carpentry phase of house construction may look simple enough. After all, you may have built a dog house or a bird feeder when you were young. In reality, however, framing, roofing, and siding are highly technical fields with skills, terms, and procedures that must be mastered to build a sound home. Framing A builder may select a particular framing approach from a variety of effective techniques. However, this section will explain the rough carpentry phases of constructing a house in general terms without emphasizing any particular technique. Planning Materials and Techniques Long before construction starts, the builder plans the framing of the house. Since the framing is anchored to the foundation, the builder must plan these two parts of the house together. Planning the details of framing is also part of the design process. For example, such things as the planned roof line and the location of the interior walls and stairwells will affect the plans for framing. Notice the floor framing in drawing 3.1, especially the floor joists. A joist is a beam constructed of dimension lumber—often 2x8 or 2x10—that provides direct support to either a floor or ceiling. Underneath these floor joists is a support beam held up by piers. The builder and designer determine the size of the joists and support beam and the size and spacing of the piers according to the amount of weight that the homeowner will place on the floor. Living spaces occupied by furniture and people require a structure of moderate strength. On the other hand, bathrooms with heavy bathtubs may require a stronger structure. The wall framing must take into account the size and placement of windows and doors, roof loads, and support beams. The center beam in drawing 3.1 supports a center wall that in turn braces the roof. If the builder uses a trussed roof instead, this center wall might be unnecessary. As discussed later in the section, a trussed roof has preassembled components that provide support for the roof. Once the floor and wall framing is planned, the builder plans the ceiling and roof framing together. This is because the roof rafters, or wood beams that support the roof, and the ceiling joists form an integrated roof system. Notice the wall studs in drawing 3.1. They are made of slender wood or metal columns, usually 2x4s, placed vertically in the wall. Horizontal plates of similar material correct the studs at the top and bottom. Diagonal metal or wood bracings are often used to brace the wall assembly. The builder places headers—beams made of doubled pieces of dimension lumber—in load-bearing walls above the doors and windows. (See drawing 3.1.) The header carries the load of the roof or upstairs floor above the window opening to the studs on either side of the opening. Floor Framing Once the builder has finished planning the materials and techniques for framing, the next step is to begin construction of the floor. Drawing 3.2 shows the bare essentials of floor framing. When framing the floor in most climates, the builder simply nails the joists to a sill, which is bolted to the foundation. In high-wind or coastal areas subject to strong storms, however, local codes may require builders to fasten the floor and the wall above directly to the foundation with some anchoring system. Typically, the builder places the joists on the sill plate of the foundation and on a beam or wall under the center of the structure. The lumber industry provides builders with standards for the strength of a given piece of dimension lumber. From these standards, the builder knows how many feet a floor can span from one support to another. The builder can also determine the spacing of piers needed to support the beam that in turn supports the joists. The builder usually laps and nails the joists together in the center. (See drawing 3.2.) If the builder plans to place a load- bearing wall on this floor running parallel to and between the joists, then the builder may use blocking to carry the load to the adjacent joists on either side of the wall. If a load- bearing wall rests directly on a joist, then the builder may double or triple the joist, depending on the load. Floor Framing With proper planning at the design stage, the builder can avoid beams or columns in large living areas. For example, the builder can use a steel or wood-laminated beam to extend the area beneath a floor or roof. In other words, the stronger the beam, the larger is the open area that can be created without supporting columns. In addition, to avoid having beams project below the ceiling level, the builder can attach the joists to the side of the beam to make the ceiling flush. (See drawing 3.3.) Framing of Flush Ceiling Beam The builder then attaches a subfloor to the floor joists. (See drawing 3.2.) This may be a single layer of material or two thinner layers. For subflooring in today’s homes, builders use plywood, waferboard, or oriented strand board and nail or glue this material to the joists. Once the subfloor is in place, the builder can proceed with the wall framing. Wall Framing Several carpenters usually work together to construct the walls of a house, which are typically framed with 2x4 lumber. As the first step, the carpenters use a chalk line to mark the location of all walls on the subfloor. They next lay the top and bottom plates on the subfloor and mark where the studs go on the plates. (See drawing 3.4.) Wall Framing with Platform Construction The carpenters then arrange the studs between the plates. At this point, they also make openings for windows and doors by placing headers above the openings and placing extra studs on either side to carry the load over the openings. Once the carpenters have the bottom plate, studs, and top plate in place, they nail this system together as it lies on the floor. (See drawing 3.4.) Typically, the carpenters nail special corner posts in place where walls form corners. With the traditional corner post, the carpenters nail two studs together with blocks in between. (See drawing 3.4.) The carpenters then place these two studs at the end of one wall and a single stud at the end of the other wall. That way, they have sufficient wood to nail the walls together and adequate surface for fastening the dry wall to the inside of the walls. More recently, many builders have begun using metal clips at corners for drywall support, thereby eliminating the need for one of the studs and the blocks. Either method is acceptable. Before the wall is lifted into place, a carpenter attaches either wood or metal diagonal bracing near the corners of the structure. ill. 3.4 shows a 1x4 wood brace that a carpenter has attached to the frame by cutting diagonal notches in the studs. However, many builders prefer to use metal braces, which don't require notching. The carpenters must carefully measure and attach the braces to ensure that the wall frame is perfectly square—or forming a perfect rectangle—and plumb or vertical when it's lifted into place. The lead carpenter also checks to make sure the window, door, and other openings are the correct size and in the location called for in the house plans. After the wall is nailed together, the carpenters lift it into place and support it with temporary bracing. The lead carpenter will use a level to check that the wall is perfectly vertical. The crew next straightens the wall by placing a tight string along the top and moving the wall until the top is in line with the string at all points. The crew then firmly nails the braces down to the floor to hold the wall in place. The carpenters next nail the exterior wall sections together and usually double the top plates for reinforcement. If the roof framing rests directly over the studs within the exterior walls, the double top plate may not be needed. Once the carpenters erect the walls, they then anchor them down by nailing through the bottom plate and the subfloor to the underlying joists. To provide room between the studs for additional insulation in colder climates, builders increasingly use 2x6 studs and plates for exterior walls. Also 2x6s are frequently used for walls that will contain bathroom or kitchen plumbing lines. In addition, when placing the wall, a carpenter may apply caulk under or around the bottom interior edge of the exterior walls where they join the subfloor. This step can reduce air leakage. In high wind areas, the builder may nail hurricane straps to the exterior of the wall and firmly attach the studs to the underlying structure. The builder may also apply sheets of sheathing to the exterior walls. This sheathing both reinforces the wall and provides a base for the external finish material. For this sheathing, the builder may use a rigid foam insulation, often backed with aluminum foil. Over the top of this, the builder may then apply an air infiltration barrier to reduce air leakage. Constructing the walls is labor intensive and subject to the tyrannies of weather. For this reason, many builders construct wall panels in a workshop, where tools can be conveniently put away each evening, construction can go on in bad weather, and workers can even finish tasks at night during rush times. With this approach, builders can also avoid delays by keeping a ready supply of raw materials on hand in the workshop. They can even use scraps of material left over from one job for other jobs, so no materials are wasted. If panels are constructed in a workshop, the builder loads them onto a flatbed truck, not unlike the truck that would have hauled the raw materials out to the job site. These wall panels are essentially identical to the walls built on site. However, such innovations can save on construction costs and thus contribute to a more affordable home. Ceiling and Roof Framing Traditionally, the builder frames the ceiling and roof on site with dimension lumber like the floor system. As noted in the Introduction, this process is sometimes called stick-built construction. Stick-Built Roof Framing. After the walls are up, the carpenters cut and lift the ceiling joists into place. These are typically made of 2x6s or 2x8s, usually spaced 16 inches apart. The ceiling joists, which are usually planned to run parallel to the roof rafters, hold the walls together and support the ceiling. The roof framing also includes wood rafters. (See drawing 3.1.) In a typical roof system, one end of each rafter rests on an exterior wall and a portion of the rafter may hang over the edge of the wall to provide an overhang at the eaves. The other end of the rafter slopes up to meet another rafter coming from the opposite side of the house. The rafters meet in a ridge and the carpenters then nail the rafters to a ridge rafter. About a third of the way down from the ridge to the ceiling joists, the carpenters nail collar beam braces horizon tally between opposing rafters. They usually install one collar beam for every three or four rafters as required by the local building code. In a plain gable roof, the rafters and ceiling joists form an open triangular space that becomes the attic of the house. A 2x4 gable end wall encloses the ends of the attic. (For a picture of different types of pitched roofs, see drawing 3.6.) Pitched Roof Types: (A) Gable, (B) Gable with Dormers, and (C) Hip Most new homes call for attic ventilation. Some home designs use a vent installed within the gable end wall, which may be both decorative and functional. Drawing 3.7 shows four different designs for vents (A, C, D, and E) and a cross section of a vent (B), which shows how the vent is constructed. Other alternatives include soffit, roof, or ridge vents (F). After carpenters have completed the gable end walls and put all permanent bracing in place, they apply the roof sheathing, which is usually plywood, waferboard, or oriented strand board. (See drawing 3.1.) They install the long dimension of the sheathing perpendicular to the rafters and usually stagger the sheathing to provide extra bracing. The carpenters may extend the sheathing over the gable ends to form a gable end overhang. Vents: (A) Triangular Gable Vent; (B) Gable Vent Cross Section; (C) Half- Circle Gable Vent; (D) Square Gable Vent; (E) Vertical Gable Vent; and (F) Soffit, Circular Roof, and Ridge Vents Wood-Truss Roof Framing. Many builders construct roofs with preassembled components called trusses, in which rafters, ceiling joists, and intermediate braces are fastened together with steel plates. In fact, roof trusses have become so common that many cities have specialized roof-truss manufacturers. Roof-truss manufacturers can produce a custom roof- framing system for a given set of plans. The roof-truss system replaces a roof constructed on site with ceiling joists, rafters, collar beams, ridge boards, and gable-end framing. Since a structural engineer custom designs the truss system, usually with the aid of specialized computer programs, the builder can use smaller dimensioned lumber to achieve significant savings for the buyer. Trussed roofs are engineered to span the distance between the front and back walls of the house. Since the trusses only bear on exterior walls, the builder can move interior walls around with great flexibility. This allows for the construction of large rooms that can run the entire width or depth of the house. Wood trusses are also normally spaced farther apart than stick-built rafters, which again saves on lumber costs. How ever, trusses generally only gain such savings with simple roof lines. When a roof is too complex, the truss design can become so complicated that the savings may be lost. In addition, fully vaulted ceilings are impossible to achieve with trusses. However, builders do use scissors trusses with sloping bottom members to support partially vaulted ceilings. Overall, the combination of the cost savings and the added design flexibility makes roof-truss framing an attractive way to frame a roof. Drawing 3.8 shows a simple sketch of trusses being erected. In the first step, the builder lifts the gable truss into place, often with a crane. Care is taken to make sure that this truss is perfectly positioned and exactly vertical. As indicated in the sketch, the builder firmly braces the gable truss. The builder then lifts the other roof trusses in place and temporarily braces them to this gable truss. A trussed roof does not need a ridge board. Instead the builder installs 2x4 blocks between the trusses or ceiling joists and later nails the tops of parallel walls to these blocks. 3.8 Erection of Roof Trusses Roofing After the roof is sheathed, the carpenters usually tack in place a layer of asphalt-treated felt paper. (See photo 3.9.) As part of the roofing material, this paper protects the roof sheathing from rain and sun until the roofers can apply the shingles. 3.9 Newly Sheathed Roof Covered with Felt Paper Roofing Material Roof coverings come in many different materials, textures, sizes, shapes, colors, and application styles. The choice of roof covering for a home depends on such factors as local traditions, climate, construction budget, availability of skilled roofers in the area, and the tastes of the homebuyers and designers. For example, terra-cotta tile roofing may be popular in California, Florida, or Arizona, where the Spanish tradition and local climate make this an appropriate material to use. However, finding a skilled tile roofing crew in Virginia or Pennsylvania might be difficult, where asphalt shingles, wood shakes, or wood shingles might fit better with local tastes and customs. (See drawing 3.10.) Another roofing material that builders use is slate, but this is usually limited to expensive custom homes. Tar and gravel or other forms of membrane roofing are used for flat or built up roofs. Sheet metal roofs made of aluminum or galvanized steel are also found in some rural areas. Builders still use copper for some roof parts, particularly for flashing and roofing at bay or dormer windows. In addition, sheet metal, such as aluminum or galvanized steel, is often used for edging and valley or other types of flashing. (See drawing 3.11.) Builders place flashing where the roof meets the walls or chimney to keep water from entering the house. 3.10 Wood Shingles 3.11 Valley Flashing for a Roof The most common roofing material is a 3-foot-wide, asphalt-fiberglass shingle. These shingles are sold in bundles. Three bundles cover 100 square feet of roof and are called a square. A typical square of fiberglass roof shingles weighs over 200 pounds. Since the roof of a typical three- bedroom ranch house can use 20 to 30 squares of shingles, it's easy to see why the bracing and engineering of the roof are so critical. Since a typical bundle of shingles weighs 80 pounds and must often be carried by hand up a ladder to the roof, it's also easy to see why roofing requires skill, experience, and strength! Roofing Process Once the felt paper is in place, the roofers can begin their job. To ensure proper installation of the shingles, the roofers place marks at the gable edges of the roof for the correct spacing of the shingles and then snap chalk lines between them to mark where they will nail the shingles. If called for by the house plans, the roofers may nail a metal drip edge to the bottom edge of the roof sheathing. As an alternative, the roofers may simply let the shingles hang over the eaves a bit to provide this protection. On steep or high roofs, special safety precautions are required during the roofing process. The roofers nail a starter strip of shingles on the bottom edge of the roof. Subsequent rows of shingles overlap each other to form a double or triple layer everywhere. Beginning from the lowest edge of the roof and keeping the tabs in line vertically and horizontally, the roofers then nail shingles in staggered rows up the roof. They continue this procedure up both sides of the roof until the shingles meet at the ridge. The roofers may then install a ridge vent. Alternatively, if gable vents are used, the roofers cut cap shingles that they then nail over the ridge and extend down either side of the roof. If wood shingles or shakes are used, the roofers nail a special roll roofing or flashing over the upper rows of shingles or shakes to prevent water leakage. (See drawing 3.10.) They then cover the flashing with ridge shingles or shakes. As the roofers install the shingles, they seal any vents that extend through the roof with a special collar flashing, which is pre-manufactured to the specific size needed. The collar flashing is fashioned with a flat base that lies on the roof and a collar that fits tightly around the vent pipe at the top. The upper side of the base laps under the shingles above the vent, and the lower side of the base laps over the shingles below the vent. The roofers then seal the collar with durable caulk or black plastic cement. As shown in drawing 3.11, when two roof lines meet and form a valley, the roofers must take special care to make sure the valley does not leak. One approach is to cut the shingles away and form an exposed valley that is protected under the shingles with flashing made of copper, aluminum, or galvanized steel. A more recent method is to install roll roofing in the valley and then to weave shingles from adjoining roof lines into each other to form a continuous covering of overlapping shingles over the valley. Water is then carried away over the shingles with little risk of leakage. However, this approach requires the skills of an experienced roofer. Generally, local customs dictate the method of flashing that a builder may use. Roofers also use flashing where a roof abuts a wall. (See drawing and photo 3.12.) If the wall is covered with wood, vinyl, aluminum, or some other type of siding, then the roofers nail short pieces of step flashing on top of each course of shingles and bent up under the siding, with most of the flashing covered by the succeeding row of shingles. 3.12 Flashing at Roof-Wall Intersection If the wall is brick or where the roof meets a brick chimney, then the roofers install additional pieces of flashing in the mortar joints, which fold down to cover the top edges of the step flashing. They then caulk the joints between the flashing and brick wall. On the upper side of chimneys where the roof abuts the chimney from above, the roofers construct a saddle or cricket, which is a tent-shaped projection that directs water around the chimney. A large saddle or cricket may have a ridge board, short rafters, and plywood sheathing to support the flashing. Exterior Trim Once the roofing is completed, the builder can then turn to work on the exterior trim. Most homes have some sort of eave overhang or soffit, which is a portion of the roof extending out over the side of the house. While a soffit appears decorative on most styles of homes, it serves the important function of carrying water away from the walls and foundation. In older homes in the South, a broad overhang on the south side of the house also adds shade to the windows and doors and helps to cool the home in the summer. Drawing 3.13 shows a portion of an eave or soffit that runs parallel to the ground at an exterior wall. Portions of soffit that run at an angle to the ground at a gable end wall are called rake overhangs. In drawing 3.13 a portion of the roof truss forms the underlying structure of the eave overhang. At the ends of the rafters or trusses, the workers nail a fascia board—often a 1x6—to cover the gap between the sheathing and the soffit. The fascia board may have a groove cut into it lengthwise to receive the soffit. For easier maintenance, the fascia may also be made of prefinished aluminum or vinyl. The builder usually installs the fascia before the soffit because especially with aluminum or vinyl soffit the fascia supports the soffit. The bottom of the truss structure, which drawing 3.13 shows as a short 2x4 that runs parallel to the ground, is called a ret-urn. Literally, this 2x4 returns from the end of the truss to the side of the house. In fact, it should extend to the sheathing that the carpenters apply when they frame the walls. To the bottom of this return workers nail plywood, aluminum, vinyl, or other material to enclose the soffit. The builder may then install soffit vents to openings in the ply wood or else install perforated sections of aluminum or vinyl for ventilation. After the workers apply the siding, they then nail a continuous strip of molding to the wall directly under the soffit to cover the gap between the top of the siding and the soffit and to provide additional support for the soffit. This molding is called the soffit molding. Aluminum or vinyl channels are generally used to support soffits made of these materials. If the builder applies brick on the walls, a frieze board (not shown in drawing 3.13) is often used at the top of the wall under the soffit. A frieze board is typically a 1x4 or 1x6 board and may have a decorative molding where it meets the soffit. 3.13 Eavefora Truss Roof Exterior Windows and Doors After builders have framed and sheathed the walls and completed the roofing but before they have installed the exterior siding, they can install the doors and windows. Windows Windows do three things: they admit light, provide a view, and give ventilation. Most windows installed today have double- or even triple-insulated panes. (See photo 3.14.) A vacuum or special gas in the gap between the panes reduces heat flow through the sealed unit. Low-E coatings on the glass can also increase energy efficiency at little added cost. 3.14 Window Installation Unlike small, inexpensive panes used in older, uninsulated windows, insulated panes are expensive and usually made to the full size of the window. Muntins, the wood trim pieces that divide traditional windows into small sections, actually provide support in older, uninsulated windows. However, muntins are just decorative pop-in pieces in newer, insulated models. Window Styles. Many home designers make good use of the latest varieties and innovations in window styles to enhance both the appearance and functional value of the home. The most common type of window in traditional homes is the double-hung window. (See drawing 3.15.) The most common frame material for windows is still wood, although vinyl, metal, or combinations of these three materials are also common. In the more exotic models, the sashes pop out or tilt in for easy cleaning. Also, window screens are often built into the window unit. 3.15 Common Window Styles Another common type of window, particularly in more contemporary homes, is the casement window, which usually swings out by using a hand-cranked gear or lever. An awning window is essentially a casement window built to open horizontally. (See drawing 3.15.) Electric openers and remote controls are available to open high windows. In fact, coupled with a remote-controlled electric opener, an awning window can become a handy ventilation device in the peak of a vaulted ceiling. Stationary or fixed windows are available in rectangular picture windows (see drawing 3.15), as well as a variety of decorative shapes. Triangular or trapezoidal windows can provide light from triangular gable walls in contemporary homes with vaulted ceilings. In addition, many traditional styles of homes have featured round or octagonal windows for centuries. Finally, some builders use horizontal sliding windows, sometimes combined with a fixed panel. The most common version of this type of window is the sliding glass door, which provides a broad expanse of light to open up another wise small room and offers access to and from the house. Window Selection. The choice of window style affects the appeal, value, and livability of a new home. When selecting the appropriate style, material, and type of window for a home, the builder, designer, and even a window specialist may meet to discuss the full range of options. As part of that process, they may consider the following factors: • style of the home—The choice of window style should fit into the design of the home. For example, builders typically use double-hung windows with muntins in tradition al styles of homes, while casement, awning, or horizontal sliding windows appear more commonly in contemporary homes. • budget—Most suppliers have several styles of windows available at affordable prices, with more expensive windows offering many additional features. • materials—Wood, aluminum, vinyl, vinyl-covered wood, or fiberglass-reinforced plastic windows go with either contemporary or more traditional homes. • maintenance—The builder should consider maintenance when selecting windows. For example, where the budget allows, the builder might use one of the tilt-in models that aid in cleaning the exterior surface of the window. • manufacturer—In selecting windows, the builder also considers the reputation of the manufacturer to make sure that the windows come from a reputable source. • insulation, light, and air—Finally, in selecting windows, the builder will also consider their energy efficiency. In northern regions or where air conditioning is used, finding windows that prevent air leakage and provide superior insulation may top the builder’s agenda. In milder climates, lighting and ventilation may become more important. Doors 3.16 Pre-manufactured Door and Exterior Trim Once the builder has chosen the windows, the next step is to select the doors. Like windows, doors come in many types, styles, and materials. In fact, the same manufacturer that provides the windows may also provide the doors and related trim materials. (See photo 3.16.) Again, the house plans largely dictate the style of doors and trim that the builder uses. For example, a builder would avoid colonial trim for the door frames of a contemporary home. Similarly, high-tech door styles would look out of place for the entrance of a colonial home. Some manufacturers offer fiberglass or steel doors in a wide variety of styles, including traditional and contemporary. These doors are usually filled with foam to conserve energy and include other energy conservation features, such as insulated glass and magnetic weather-stripping. Some fiberglass doors are even stainable. Once the exterior doors and windows are selected and the windows or at least the window frames are installed, the builder can next install the siding. Siding Material Buyers’ preferences, climate, local customs, availability of material, construction budgets, and the design of the house determine a builder’s choice of siding material. In many areas, home builders have traditionally used a wide array of wood material for siding, which they can finish naturally, paint, or stain. Some types of wood-based products, such as hardboard siding, are also used for siding material. In addition, brick, stone, or stucco siding are common in many areas of the country, while vinyl, steel, and aluminum siding are also popular because of the lower maintenance and cost. However, this list is in no way complete. Builders may use wood shingles, adobe, decorative concrete block, textured poured concrete, fiberglass, metal, and even more exotic materials for siding. Some new homeowners have even chosen to build their homes into the sides of cliffs where they use packed dirt mixed with Portland cement as siding material. However, brick and stone, stucco, and wood are still some of the most common siding materials used on new homes today. Brick and Stone Brick and stone are common siding materials in the East, Midwest, and South. They provide the ultimate in durability and low maintenance but generally are more costly to install. Additionally, the type of stone or specific color of brick the builder can use depends on the location and availability of the material. Your author wanted to duplicate a special brick color from bricks made in the 1940s for a remodeling project. Unfortunately, while the manufacturer was still in business and the style of brick was still available, the special color came from clay found only in one quarry, which is now covered by a lake. Planning for a brick exterior, called brick veneer when in stalled over a frame wall, must begin early. With this type of exterior, the builder constructs the foundation with a ledge at the finish grade to accommodate the brick exterior surface. In addition, brick and stone are porous materials. If these materials are used for siding on a home, the builder should place asphalt-treated felt over the sheathing before laying the brick and should install weep holes near the bottom of the wall. Stucco Popular for many years in many parts of the country, traditional stucco is a cement-based product installed in several coats over a metal lath that is nailed to the framed wall. (See photo 3.17.) The final coat sometimes has a pigment that gives the wall its color in place of an additional coat of paint. Recent advances have allowed builders to use synthetic materials to give homes that distinctive stucco-like finish. 3.17 Stucco Application Wood Builders prefer to use wood or wood-based materials that are easily painted, easy to work with, and relatively free from warpage and splits. Common woods that have these qualities include cedar, several varieties of pine, and cypress. Builders also use western hemlock, Douglas fir, spruce, and poplar. (For an example of wood siding, see photo 3.18.) 3.18 Wood Siding 3.19 Vinyl Siding Installation If the wood is to be painted, the builder selects wood as free from knots as possible. Wood tends to shrink and expand with the seasons and natural weathering of the siding is inevitable, so paint will not last forever. However, an experienced builder can determine what type of wood best suits the climate of a particular area and what type of paint and how many coats to apply. Many wood siding products come with one rough and one smooth side. If the builder plans to stain the wood, then the rough side may be exposed to the exterior. Otherwise, the smooth side is preferable for painting. One common way to apply wood siding is as horizontal lapped siding. With this type of siding, the builder begins at the lowest point on the wall and nails long strips of wood horizontally upward until reaching the underside of the eave, with each subsequent piece lapping the piece below it. Builders can also install some types of wood siding in vertical or even diagonal patterns. One method that is popular for some contemporary home styles is to use rough-sawn boards and battens nailed vertically. Battens are narrow strips of wood that cover the vertical joints between the boards. Builders can arrange these boards in different pat terns to suit the particular design of the house and tastes of the homebuyers. They can also vertically install and stain some plywood and other types of panel siding material to give a similar effect. In this case, the manufacturer cuts grooves in the panels at the factory to simulate the appearance of boards and battens much less expensively. Other types of siding include wood fiber products like hardboard or aluminum, steel, or vinyl siding. Builders typically install all of these types of siding horizontally. (For an example of vinyl siding installation, see photo 3.19.) Further more, these products usually come pre-primed or prefinished to reduce the painter’s chores. Painting and Staining. Once the wood or wood-product siding is installed, the builder often has the siding painted or stained. The builder will also usually have the exposed wood surfaces in brick- or vinyl-sided homes painted. Exterior painting has three basic steps: priming, caulking, and finish painting. The prime coat of paint protects the surface of the wood from moisture. Particularly in humid climates, the painter primes the wood siding and trim as soon as possible after it's installed. After priming, the painter caulks all cracks, joints, and seams thoroughly with a caulking material designed to work well with the selected paint. In areas where the humidity shifts throughout the year, wood joints expand and contract, and the caulk must be able to withstand these changes. As the final step, the painter applies the finish coat of paint. For some situations, the painter may recommend two coats of exterior paint. While a bit more expensive, this approach is more durable. Stains may be less durable than a good paint job, but they are easy to reapply and are often preferred for a more natural appearance. Ventilation The builder determines the type of attic ventilation early in the home design phase. (See drawing 3.20.) In southern climates, adequate attic ventilation can lower the average attic temperature by as much as 50 degrees during the hot summer months. This reduction in attic temperature can reduce cooling costs in hotter weather. Besides controlling the temperature in the summer, attic ventilation is needed to prevent moisture from accumulating in the winter. 3.20 Inlet for Attic Ventilation Builders typically use gable vents (louvers) or a ridge vent and soffit vents for attic ventilation. (See drawing 3.7.) Hot air in the upper most reaches of the attic is carried out of the gable vents or a ridge vent by convection. As the hot air leaves the peak of the attic, cooler air is pulled in through the soffit vents to replace it. Building codes specify the minimum area of ventilation that the builder should provide. If the builder does not install soffit vents, the other vents must be substantially increased. Homebuyers in the hottest climates may want some type of power ventilation. The house may need either turbine fans powered by the wind or electrically operated power vents. Either way, adequate ventilation of the attic is a must to reduce cooling costs and moisture in the attic and to help the insulation system in the home do its job properly. The choices made in framing, roofing, and siding affect subsequent steps in the construction process. Special care must be given to planning the framing process, the roofing material, the doors and windows, and the type of siding—whether brick, stone, stucco, vinyl, aluminum, steel, or wood—because each of these choices affects the final result. After the steps for framing, roofing, and siding are completed, the builder can move on to the plumbing, heating, and electrical work for the house.
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