Remodeling Attic Walls

Knee Walls

• Remodeling an attic often involves building knee walls, which take up less space than normal walls. A typical attic knee wall might be 4 or 5 feet high. You can build a knee wall the same way you frame a typical partition wall, except that you use shorter studs. The bottom of the knee wall, the sole plate, should be nailed into the floor joists. The top of the knee wall, the top plate, fastens to the rafters.

End Walls

• End walls, the larger walls at each end of the attic, fit between the two knee walls. The sole plate consists of a long horizontal beam as in normal walls, but the top plate often requires three sections. One framing member is horizontal, but the two plates on either side of the horizontal plate follow the slope of the roof. You can nail the top plate sections either to the rafters or to the blocking placed between the rafters.

Insulation

• Insulating the remodeled ceiling requires placing fiberglass batts into the wall cavities before applying the finishing material, such as drywall. You can also insulate the back of the knee wall and the open spaces between the rafters behind the knee wall for best results. The spaces between the floor joists are usually filled with insulation, regardless of whether the attic is finished or unfinished. However, you do not need to add insulation to the rafter spaces above the room's ceiling.

Considerations

• Before starting any basement remodel or wall construction, ensure that the space meets local building code requirements, which usually follow the International Residential Code, or IRC. For example, the IRC stipulates that at least half of the habitable space in an attic has a ceiling height of 7 feet or more. Also, the floor joists must have the strength to support any wall you construct. Consult with a structural engineer before beginning any work.