IS TRUSS DEFLECTION A PROBLEM
IS TRUSS DEFLECTION A PROBLEM
(OP)
When a run of roof trusses deflect different amounts, does this present a problem? For example. Let's say you have run of 5 standard commons, then the run of trusses changes to 5 attic trusses boxed out for an FAU. Say the deflection (in the center panel) for the attic trusses are twice that of the standard commons--in the same panel. What are the negative ramifications of this? How should you handle this? References to any articles that address this will be appreciated. Thanks.





RE: IS TRUSS DEFLECTION A PROBLEM
I don't think there is any "Code" about deflection from truss to truss, specifically.
RE: IS TRUSS DEFLECTION A PROBLEM
RE: IS TRUSS DEFLECTION A PROBLEM
CTruax is correct --- try to get cambers set correct or strong back. I have even used 2 or 3 "extra" trusses until they reached a natural "break" or wall!!
This can also be a real problem in floors where joists of varying spans meet up. One is short and one is very long although both are acceptable concerning loads and deflections....
RE: IS TRUSS DEFLECTION A PROBLEM
RE: IS TRUSS DEFLECTION A PROBLEM
A 7' setback hip girder with a bearing post is a common problem. The 9' setback truss will deflect a lot more.
RE: IS TRUSS DEFLECTION A PROBLEM
At the floors, I am always trying to avoid intermedoiate hard points where possible. These can give unsightly reads in the floor molding. Doubling or trippling trusses in the area for two or three joist bays helps to spread out the deflection difference here too, as in 3,2,1,1,1, etc.
Mike McCann
McCann Engineering
RE: IS TRUSS DEFLECTION A PROBLEM