Exterior walls 37 Exterior siding 38 Wood siding 38 Aluminum siding 40 Vinyl siding 41 Asbestos-cement shingles 41 Asphalt siding 42 Stucco 42 Synthetic stucco (EIFS) 43 Veneer wall 44 Masonry wall 45 Trim 45 Windows 46 Inspection 48 Exterior doors 49 Storm windows, screens, and storm doors 51 Storm windows 51 Screens 51 Storm doors 52 Inspection 52 Caulking 52 Checkpoint summary 53
As you walk around the house inspecting the further investigation. If by the end of the house paved areas, you should also inspect the exte-inspection you cannot determine the cause, rior walls, windows, trim, and doors. Before you should have the condition checked by a actually inspecting these items, however, look professional. at the overall wall area for indications of past While inspecting the exterior walls, also or current structural problems. Are the win-note for further investigation any pipe or hood dow and door lines square? Are any portions projecting through a wall or basement window. of the walls sagging or bulging? Are the walls These items are usually not problem conditions, and corner sections vertical? A problem condi-but it is useful to understand their function. The tion should be recorded on your worksheet for hood is often covering the discharge end of an exhaust fan or clothes-dryer duct, and the pipe may be the discharge line for a sump pump or condensate line from an air-conditioning system. If the pipe is connected to a sump pump, it might indicate a past or current water-seepage problem. Sump pumps and water seepage are discussed in detail in chapter 11.
The exterior walls in most residential structures will be either wood frame or masonry, sometimes a combination of the two. The latter is commonly called a veneer wall. The exterior walls rest directly on the foundation and are bearing (load-supporting) walls. They support the roof, floors, and vertical loads imposed by other building components. The outer covering of the exterior walls provides protection from the weather and, if properly installed, minimizes the flow of air, moisture, and heat into or out of the structure.
When the walls are wood frame, the vertical framing members (studs) support all the vertical loads, and the outer finish covering (generally called siding) provides weather protection. Insulation is normally located in the spaces between the studs. In masonry walls, the masonry (clay tile, brick, stone, concrete block, etc.) provides both the structural support and the weather barrier. A masonry-veneer wall is a wood-frame wall with masonry used in place of the siding. Although the masonry in a veneer wall is not used for supporting the vertical loads, it does support its own weight.
Basically, a wood-frame exterior wall consists of 2-by-4-inch or 2-by-6-inch studs covered on the interior side by materials such as plaster, Sheetrock, plasterboard, wood, or hardboard panels (as described in chapter 10) and on the exterior side by sheathing, sheathing paper, and the finish siding. (See FIG. 5-1.) In some parts of the country where rot and termite activity are problems, metal studs are now being used in place of wood studs.
Sheathing is installed over the studs to provide bracing and minimize air infiltration. Depending on the type of sheathing, it can also be used to form a surface onto which the exterior finish can be nailed. Wood boards, plywood, fiberboard, and plasterboard are often used for wall sheathing. Fiberboard sheathing adds a small amount of insulation to the overall exterior wall; however, it should not be used as a nailing base for the direct attachment of the exterior siding. Rather, the siding should be nailed either to the studding through the sheathing or to wood nailing strips that have been attached to the sheathing. In many communities, when the exterior siding is capable of supplying adequate bracing and weather protection (as with exterior plywood panels), the sheathing is often omitted.
The purpose of the sheathing paper is to resist the direct entry of water during a driving rain. Sheathing paper (an asphalt-saturated felt) is water-resistant but not vapor-resistant and allows water vapor (which often builds up in the voids of the frame wall) to escape rather than condense and cause problems. Sheathing paper can also be very effective in reducing air infiltration.