Question on deflection of sloped wood rafters
Question on deflection of sloped wood rafters
(OP)
Hi, I have a question on calculating deflection on sloped wood roof rafters. I'm working on a project where I am checking existing roof rafters on a residence. I have calculated my dead and live loads on the horizontal projection and using the horizontal span of the rafter to check strength. When checking deflection, 5wL^4 / 384EI, is the horizontal span and associated loads on the horizontal projection used for w and L?
Thanks.
Thanks.






RE: Question on deflection of sloped wood rafters
RE: Question on deflection of sloped wood rafters
Mike McCann
MMC Engineering
RE: Question on deflection of sloped wood rafters
RE: Question on deflection of sloped wood rafters
And for your deflection check, I am assuming you may have a trussed roof? If so, you'll need to add the deflection from the truss action as well as local bending of the top chord (2x6), assuming you have ceiling joists acting as the bottom chord and it is a gabled roof.