Can I remove the interior walls under a roof truss?
Tuesday, January 7, 2020
Yes, you can. Residentiall roof trusses are designed to bear only on the exterior walls at each end of the span. But there are five possible exceptions to look out for:
1) When the home has an L or T shape, there may be an interior bearing wall under the intersection of the perpendicular rows of trusses. But, even in that situation, there is usually a doubled or tripled-up truss at the intersection, instead of an interior bearing wall, that provides bearing along the bottom chord where the perpendicular trusses meet.
2) Truss chords have been removed. This is sometimes done by a homeowner to provide cleared space in the attic for storage, but destroys the structural integrity of the truss.
3) Only part of the roof framing may be trusses and the rest is rafters, as in the photo below. There may still not be any interior bearing walls, but you should check carefully.
4) What looks like trusses is actually rafters and purlins. Purlins and kickers are braces perpendicular to rafters at approximately the center of the rafter. The kickers resemble truss chords, but they bear on an interior wall below and are usually not at every rafter.
5) The trusses have plywood gusset plates. Some older homes have trusses that were made at the homesite using plywood gusset plates, like in the photo below. A gusset plate is the connector piece between the parts of a truss, and manufactured trusses use metal ones. Trusses with plywood gusset plates are usually older, often not designed by a professional engineer, with undersized plates and inadequate nailing—like in the photo below. These trusses are rarely seen nowadays. We do not recommend removing walls under them.
And, of course, when in doubt consult a construction professional before proceeding with removal of any interior walls. Also, remember that there will be electrical wiring, and possible plumbing, to deal with as part of the wall removal.
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