Interior Shear Wall Connections to Trusses
Interior Shear Wall Connections to Trusses
(OP)
I'm a plans examiner looking at a lot of residential designs. Many have interior shear walls when there are a lot of windows. The interior shear walls (of course) are either parallel or perpendicular to the trusses. The walls that are parallel may or may not be directly under a truss. The walls which are perpendicular to the trusses will fall under several trusses, but the load will be across the plane of the truss. I've learned that if the wall is parallel to and directly below the truss, you can sheath the wall up to the roof and design for increased horizontal load. I realize that interior shear walls can have more shear load than end walls. How can these connections be safely designed?





RE: Interior Shear Wall Connections to Trusses
RE: Interior Shear Wall Connections to Trusses
Thanks
RE: Interior Shear Wall Connections to Trusses
RE: Interior Shear Wall Connections to Trusses
I think that gives me what I was looking for. If you block it right it's OK
RE: Interior Shear Wall Connections to Trusses
For interior shear walls perpendicular to trusses, the truss manufacturer can fabricate shear-blocking panels that install between the trusses and atop the shear wall. This provides a method of transfering the roof diaphragm load, through the panel and into the shear wall. Otherwise the sheetrock ceiling will act as a diaphragm and discontinuity occurs to the roof ply.
A framer can site-build a continuous shear-wall transfer through the attic also.
At exterior walls, and typically a truss heel joint, frieze blocking acts like a short panel. Boundary nailing is needed from the roof-ply into the block, and typically LTP4 transfers the horizontal load to the double top plate.
Interior parallel truss & shear walls that align are the best. Sometimes an additional truss is added to insure alignment. Blocking between trusses with a block-to-top-plate connection will not transfer much load and is not advised.
Multiple shear walls in alignment can rely on the top-plate to act as a collector to transfer the lateral load to the truss.
RE: Interior Shear Wall Connections to Trusses
Thanks for your reply. Your comments are more in line with my initial concerns, and those of a truss design engineer I was able to find. By his rough calculation the shear force on shear panels built between the trusses (for trusses perpendiculat to the wall) was pretty high.
What I forgot to ask, and seems contradictory, was what happens when there is a porch attached, and the house wall is the shear wall. This seems to be the same situation.
RE: Interior Shear Wall Connections to Trusses
The roof ply boundary at the truss heel is transfered back to the wall top-plate through a horizontal ceiling diaphragm, or
the shear wall continues up to the roof-ply through truss blocking panels or site built framing, or
an exterior beam supporting the truss heels acts as a collector to drag the total lateral load to another in-alignment shear wall or truss collector.
RE: Interior Shear Wall Connections to Trusses
lotklear