Collar Tie's

[musick]

Retired Contractor here.
My question is placement and size of collar ties.
Span is 25'3", 2x6 rafters. I have a "bearing" wall 13'6" from slab to rafters. Roughly 1'off center from 2x8 ridge.
My ties will connect to the wall studs as well as the rafters.
I had planned in the upper 1/3 making it 32" above the plates and a length of approx. 10'
Will this work? and size of ties?
Thank you for any advise.

 

[phamENG]

Just to make sure we're using the same terminology, are you talking about rafter ties or collar ties? Connecting to the wall studs and rafters sounds like a rafter tie (usually a ceiling joist). But upper 1/3 would be a collar tie. Rafter tie keeps the gable from spreading, the collar tie fixes the ridge and keeps it from separating under unbalanced wind and snow loading.

You can draw out a sketch and it'll help. What was your trade? If you were a framer/carpenter, you should be able to get through the IRC easily enough. Conveniently enough you're in Virginia. So am I, so my references should work well for you. Here's a link to Chapter 8 of the Virginia Residential Code. It has tables that spell out span lengths and required sizes, as well as adjustments depending on variable heights of rafter ties.

 

[musick]

Thank you phamENG
I was a framer for many years. I know the code use to state, collar ties in the upper 1/3 of attic space.
I read the code had changed to the lower 1/3 unless designed. Now, I think it may have been the IRC code changed, because from my understanding r802.4.6 states in the upper 1/3, exactly my plan. I realize I will need to sister the rafters.
anyway I will upload the print.
Thank you

 

[phamENG]

Ok - thanks for the sketch. So what you're proposing doesn't fit as nicely into the prescriptive code. Looks like you have pretty typical construction on one side, and a vaulted ceiling on the other. You'll need to do one of two things: use a ridge beam OR cantilever the joists on the right over the bearing wall and use the cantilever ends to support the rafters that don't have a rafter tie. Seems plausible, though.