pitched cieling joists

[myvalk]

im adding a room to my house, and the mrs. wants higher than normal ceilings. if i framed the roof with a 6/12 pitch and then the ceiling with a 4/12 pitch, not butting them together like roof rafters, but bypassing them to the other side rafters, and fastening them to the rafters,kind of like a big "X" would that also serve as collar ties?

[Cole]

Yes it would but Im not sure if that is up to code!!

[Dragon]

You'll need to ask your local inspector that one. They might allow it, might not.

[myvalk]

hope this works

http://pg.photos.yahoo.com/ph/geggy444/detail?.dir=/7de5&.dnm=8223.jpg

[myvalk]

;-)

[Tom R]

Doesn't sound quite 'functional' enough as a collar tie system. Why not just add 'real' collar ties at your '4-12' point?

[Tom R]

Or even a little lower - - for a 'coffered' look.

[myvalk]

ok... now dems dere are some good thoughts ( say with a brooklyn accent.)

[myvalk]

ok...now for the tricky question.
given a 6/12 roof, how far down would i put the collar ties, so as to keep maximum ceilng height?
the ridge would be about 6' higher that the top plates.

[Dragon]

ok...now for the tricky question.
given a 6/12 roof, how far down would i put the collar ties, so as to keep maximum ceing height?
the ridge would be about 6' higher that the top plates.

What is the length of your rafter? Local code here has a 12 ft. span limit before a rafter must be supported in some fashion. Meaning, 12 ft. maximum between top plate and collar tie along the bottom length of the rafter.

[myvalk]

as my cad program shows it, it should be
12' 9 1/16" along the bottom of the rafter.
but if i dropped the collar tie down, say, 3' from ridge, would that be enuf to hold walls in from spreading?

ps thanx for responding

[mjpliv]

Although not the definitive answer, a good rule of thumb would be the lower third of your total rise, or in your case, about 2' above your top plate. The reason you use a percentage of your total rise instead of the rafter length is that steeper pitched roofs have lower lateral (outpush) forces than lower pitch roofs meaning the collar ties can be placed farther from the plate on a steeper roof using the 30% of the total rise formula.

[myvalk]

kool... thanx again .