jgeng
Structural
- May 23, 2009
- 61
I have a conventionally framed roof with a collar tie in the upper third. The pitch is 9:12 and the there is no rafter tie or ceiling joists. The ridge is not sized to be structural. The rafter tie needs to be there to prevent thrust which has already pushed these walls out some.
My question is not whether a rafter tie should be there it is whether it is explicitly required by code (IBC)? I was planning to engineer an alternative to keep the ceiling height higher. Perhaps forming a scissor type truss with bracing members from the rafter at the wall end up to the collar tie or incorporating a wide top plate at the wall to give it rigidity from being thrust out from the deflection.
Another question code (IBC) requires Joists to be laterally restrained at ends by blocking or other means. My question is whether anyone could justify joists that overlap and are nailed to eachother over a support provide restraint. I have marine/residential type structure; in looking at the following manual (see link) how are the structures depicted exempt from joist end blocking?
My question is not whether a rafter tie should be there it is whether it is explicitly required by code (IBC)? I was planning to engineer an alternative to keep the ceiling height higher. Perhaps forming a scissor type truss with bracing members from the rafter at the wall end up to the collar tie or incorporating a wide top plate at the wall to give it rigidity from being thrust out from the deflection.
Another question code (IBC) requires Joists to be laterally restrained at ends by blocking or other means. My question is whether anyone could justify joists that overlap and are nailed to eachother over a support provide restraint. I have marine/residential type structure; in looking at the following manual (see link) how are the structures depicted exempt from joist end blocking?