Things You'll Need
2-inch by 4-inch framing lumber
16d framing nails
Drywall or other wall covering
Not all stairways are enclosed. Stairs to an unfinished basement often may be left open in original construction; however, a homeowner who wants to transform that into living space will want to add a wall. Some stairs to basements are built along one wall, but finishing that basement for a playroom, workshop or other use will require adding a wall along the stairway. Building a stairway wall is much like building any partition wall that bears no load. A stairway wall needs a top plate, bottom plate and vertical studs in between.
Measure the height and length needed for the stairway wall with a tape measure and identify ceiling joists or wall studs for fastening points. Make the stairway wall as long as the stairs and the height from floor to whatever ceiling is above the adjacent space. Use open joists in a basement.
Build a wall on a flat surface, like a basement floor, if possible; the alternative is to fasten top and bottom plates and build the wall in place. Frame a basement wall with 2-inch by 4-inch studs 1 ½ inches shorter than the height from floor to ceiling; thus, it can be easily erected.
Make a wall frame first, with top and bottom plates the length of the wall and studs on each end. To square the wall, measure corner to corner and adjust the frame until the diagonals are equal. Add studs at 16-inch intervals between the end studs. Fasten studs with 16d framing nails driven with a hammer through the top and bottom plates — two nails into each end of each stud.
Raise the wall and slide it in place. Brace it temporarily with 2-by-4s nailed to studs and set on the floor along the wall. Put it tight against the stair treads or leave a 1/2-inch gap for drywall. Slip another 2-by-4 into the 1 1/2-inch space at the top of the wall. Use tapered wood shims to adjust the wall until it is plumb; shims will hold the wall in place temporarily.
Fasten the bottom plate of the wall to the floor. Use concrete nails in a basement and framing nails in a wood-framed space. Toenail the two top plates together and to the joists above with framing nails driven diagonally through both plates into the joists. Remove the braces once the wall is secured.
Cover the wall with drywall, paneling or other material of choice. Install a handrail, fastened to the wall studs from top to bottom.