Top chord bearing wood floor truss attachment to ledger on CMU?
Top chord bearing wood floor truss attachment to ledger on CMU?
(OP)
thread507-352349: wood floor trusses to exterior bearing wall
How would you attach top chord bearing wood floor trusses to 2 ply 2x wood ledger bolted to CMU 2 story wall in high wind? How would you attach 3/4" osb floor deck to the ledger? Blocking between trusses? Or maybe just lag screw the top chord to ledger, nail floor OSB to trusses only? Since this floor is a horizontal diaphragm it seems nice to nail the osb to ledger somehow. I have used top flange buckets with Ijoist and nailed osb to joists and ledger since they were all on same level but in this case top of truss is 3" above top of ledger.
How would you attach top chord bearing wood floor trusses to 2 ply 2x wood ledger bolted to CMU 2 story wall in high wind? How would you attach 3/4" osb floor deck to the ledger? Blocking between trusses? Or maybe just lag screw the top chord to ledger, nail floor OSB to trusses only? Since this floor is a horizontal diaphragm it seems nice to nail the osb to ledger somehow. I have used top flange buckets with Ijoist and nailed osb to joists and ledger since they were all on same level but in this case top of truss is 3" above top of ledger.






RE: Top chord bearing wood floor truss attachment to ledger on CMU?
2. Provide solid blocking between the trusses above the ledger extending to the plywood diaphragm and nail off. Nail the diaphragm to the blocking and the blocking to the ledger.
4. I would use a 4X minimum ledger, not multiple 2X's.
Mike McCann, PE, SE (WA)
RE: Top chord bearing wood floor truss attachment to ledger on CMU?
I am supposing you're using an MPC truss based upon your 3" top chord thickness, sometimes I've used a hanger like the pic below for a nice diaphragm transfer, but I think blocking like mike might be less expensive with 2 layers 2x blocking properly nailed
RE: Top chord bearing wood floor truss attachment to ledger on CMU?
RE: Top chord bearing wood floor truss attachment to ledger on CMU?
Mike McCann, PE, SE (WA)
RE: Top chord bearing wood floor truss attachment to ledger on CMU?
The truss design shows 3.5" bearing but designer said that is 3"bearing+.5"gap. He reran truss for 1.5" bearing and 2"gap and it worked? He said 4x6 ledger may be more cost effective than glue and screw 2-2x ledger and only one piece to put up. And they would likely put the SDS screws into crack between 2-2x every time? Since Florida is not seismic I did 6'OC tension tie to parallel CMU wall instead of 4'OC and SDS screw top chord to ledger on the perp walls.
RE: Top chord bearing wood floor truss attachment to ledger on CMU?