Proper Exterior Wall Construction Layout

Exterior Wall Components

• An exterior wall consists of a bottom wall plate and a top wall plate with wall studs fit vertically between which the horizontal plates. Builders will often assemble these wall components while they lie on the subfloor, then stand the assembled wall frame up and bolt it securely through the subfloor and into the joists that lie beneath. While the wall frame is lying on the floor, the builder can frame rough openings for doors and windows. Once the wall is up, temporary bracing is necessary until adjacent walls are in place, at which time the builder will install another top plate and connect the walls at the sides. Sheathing, which is typically 4-by-8 sheets of plywood or oriented strand board (OSB), is the last component of an unfinished exterior wall, and installs on the outside of the studs once all the walls are up.

Stud Size

• Local codes determine minimum stud size. In many communities, you may construct exterior walls with 2-by-4 wall studs, but some communities require 2-by-6 studs. The larger studs provide deeper wall space, which allows you to install insulation with a greater R-value. If you’re having an architect draw up custom house plans, she will draw the plans to accommodate local codes. If you buy standard blueprints, the architect will provide instructions for adapting the stud size, or your contractor will make on-site adjustments.

Stud Spacing

• Standard stud spacing for exterior walls is 16 inches "on center." This means that from the center of the first wall stud to the center of the next wall stud, it should measure exactly 16 inches. If you’re installing larger studs, local code may allow you to set them on 24-inch centers. These stud spacing measurements correspond with the dimensions of collaborating construction materials such as 4-by-8 sheets of plywood and drywall, and the nailing patterns on some types of siding.

Headers

• When laying out the walls, you’ll have one or more doors and numerous windows. To install these, you must cut through some wall studs and, since exterior walls are load-bearing, you’ll have to transfer the weight load from the cut studs to the adjacent studs. You accomplish this by installing headers, cut from larger dimensional lumber, usually 2-by-10s or 2-by-12s, doubled, and then installed flat between the side studs at the top of the opening. Local codes regulate the lumber size for headers. You’ll also need trimmer studs, which are double side studs and short “jack” studs beneath a sill and above a header for stability.