How to Build a Wall to Hold Rafters

Frame an exterior wall that will support rafters while the wall is lying down. It’s much easier to attach the wall studs to the top and bottom plates while the lumber is flat on the subfloor.

Snap a chalk line on the subfloor to represent the inside edge of the wall. The edge of the sill plate, which should align with the edge of the subflooring, represents the outer edge. If you’re framing the wall with 2-by-4s, the chalk line should be 3 1/2 inches from the edge. If you’re using 2-by-6s, it should be 5 1/2 inches from the edge.

Lay two pieces of dimensional lumber the same length as the new wall side-by-side. These will be the top and bottom wall plates. While holding them together, make pencil marks across both that represent the position of the wall studs. Standard stud spacing is 16 inches on center. This means the center point on each stud should be exactly 16 inches from the center point of the next stud.

Spread the top and bottom wall plates apart and position the wall studs between them, lining each stud up with the corresponding marks on the two plates.

Nail the plates to the studs using a framing nailer and 16d nails. Insert two nails, from the outside of the plates into the bottom or top of each wall stud. If you’re building a 2-by-4 wall, insert two nails, evenly spaced. For a 2-by-6 wall, use three nails, evenly spaced. Connect both the top and bottom plates to each wall stud in this manner.

Stand the wall up and position it so the inside bottom plate aligns with the chalk line on the floor and the outer edge aligns with the edge of the sill plate.

Nail the wall in place by shooting two nails beside the bottom of each wall stud through the floor plate and into joists that run beneath the subflooring.

Temporarily brace the new wall by nailing long pieces of lumber to the wall and to the subfloor to keep it from falling while you construct adjacent exterior walls. How to brace it doesn't matter as long as you don't trip over the braces.

Build the exterior adjacent walls as you did the first wall, stand them up, and attach them to the joists the same way. During the attachment process, remove the temporary braces, and use a carpenter's level and a carpenter's square to check that the walls are straight and plumb. You might have to nudge, push or pull different parts of the walls to accomplish this.

Install a tie plate on top of the top wall plate. A tie plate is another piece of dimensional lumber that extends across the top of a wall and over the corner of the adjacent wall, tying the two walls together. Nail the tie plate to the wall plate, inserting two 16d nails over each wall stud. The tie plate will run all the way around the top of the wall.