Interior walls usually do not bear weight, so they are easier to build than exterior, load-bearing walls. A simple interior wall is made from a horizontal top plate nailed to the ceiling, a sole plate attached to the floor directly under the top plate, and a series of parallel vertical studs spaced at 16- or 24-inch intervals.

Calculate the lumber needed to place a stud every 16 or 24 inches, as specified by local building code. Add the lumber needed for the top and sole plates, as well as for ceilingblocking. Include door framing materials, if needed.

Nail top wall plate directly into the joists if the new wall runs perpendicular to the existing ceiling frame members.

Install 2 × 4 blocking between joists if new wall is parallel to, but not under, joists. Attach blocking with 8d nails. Blocking provides anchoring surface for new wall. If ceiling joists are not accessible for blocking, install wall directly under joist.