Wood Connection Question
Wood Connection Question
(OP)
I currently have a wood plate attached to the top of a concrete wall supportin wood roof trusses. The trusses were built with a heel height that was 4.5" too short. Our solution is raise the trusses and bolt (3) more 2x plates to the existing one. When you analyze this connection using NDS can you consider your main member 4.5" thick and your side member 1.5" thick? Do the yield limit equations still hold for multiple plies that are unconnected? How should the connection be designed? I need to transfer about 400plf of shear load out of the roof diaphragm. Any help would be great.






RE: Wood Connection Question
Mike McCann
MMC Engineering
RE: Wood Connection Question
The one that I would really like to know is whether or not the NDS equations are still valid for unconnected plies connected together at certain intervals. For my case I guess what does it take for the NDS equations to be valid for attaching (3) 2x8s flat to a single or double plate that is already installed on top of the wall with anchor bolts.
RE: Wood Connection Question
I agree with msquared48, use nails and A35 clips to transfer the shear force. Two (2) 10d common nails spaced at 12" o.c. would give a little over 400 plf capacity using a duration factor of 1.6.
Another consideration...with the increased sill plate height, what measures are being taken to transfer any uplift forces from the truss into the concrete wall?
Nick Deal, P.E.
Michael Brady Inc.
http://www.michaelbradyinc.com
RE: Wood Connection Question
RE: Wood Connection Question
RE: Wood Connection Question
BA
RE: Wood Connection Question
RE: Wood Connection Question
If the shear is applied perpendicular to the wall, you must also consider the overturning of the stack of plates. At the top of concrete, the moment will be 400# * 6" = 2400"# per foot of length.
I tend to agree with the suggestion that it would be better to modify the wood trusses to provide the required heel height.
BA