Wall Construction Simplified
There are two main types of wall construction, interior walls, and exterior walls. Although performing a basic function of dividing and defining space, they also provide sound and heat controls, a space for installing utilities, separation from the outdoor elements, as well as structural support for the building.
Walls are built as two primary components, they are the structure, and the finish materials.
The structure is used to house service utilities, provide support for the upper portions of the building, and as means of attachment for finish materials or insulation. They are constructed in two major divisions, interior walls, and exterior walls.
Interior wall structure is constructed in two primary categories, load bearing, and non-load bearing. Although not common, many homeowners opt to insulate the wall system to reduce sound transmission and lower heat loss in unused rooms.
Interior load-bearing walls are primarily constructed of 2"x4" or 2"x6" dimensioned lumber, with a two top plates, and one bottom plate, nailed to vertical members called "studs" spaced 16" apart. They are located over bearing beams, columns or footings, capable of supporting the loads that will be placed on them. Most often, load-bearing walls are installed perpendicular to, and as support for upper floor joists, ceiling joists or framed roof assemblies. Openings in load bearing walls are installed with headers, or small beams, supported on shorter studs, spanning the required height and width of the opening in the wall. Often cross bracing is required to prevent parallel deformation from external forces, and holds the building square.
Interior non-load bearing walls are installed in locations where the upper structural components do not rest or require support. They are built usually from single top and bottom plates, with studwork, often on 24" centers, nailed to them. Locations that this type of wall is used include walls parallel to joists, and in buildings with clear spanning truss's or manufactured/framed joist work. Openings in these walls generally do not require the use of structural headers or supports, but often do need diagonal bracing to prevent lateral movement.
Exterior walls always provide support for the upper structure, including floor and roof assemblies. They are always load-bearing, requiring diagonal supports or shear panels, and enough space for insulation. In Northern Ontario, these walls are generally constructed from 2"x6" material, but often double wall systems for added insulation are constructed. In the wall assemblies, windows and doors are installed to provide access to the building, as well as allowing for natural light or ventilation of the indoor environment. They are constructed from a framework of studs, usually 16" apart, nailed to a double top plate, and single bottom plate. Within the cavity, utility lines and insulation is placed. The interior surface is treated with a vapor barrier, and finish, with the exterior surface having an air barrier and exterior finish or "siding" installed. Openings are framed with beams or lintels, supported on shorter studs, called "jacks", and nailed to the top and bottom plates. Although there are many configurations, builders utilize, for diagonal support, it is most often installed as shear panels, which are sheets of plywood or aspenite, nailed to the exterior of the walls framework. Other methods of diagonal support include wood or metal wind bracing which is a member placed diagonally from the bottom plate, through the studs, to the top plate.
There are two main areas on walls over which a finish will be applied, they include the interior exposed surface and the exterior exposed surface. The finish materials provide an esthetic surface, protect the utility lines, and reduce the transmission of sound and heat.
Interior exposed surfaces
Finishes applied to interior walls are very much the more important consideration to homeow