Expert: Daniel Humphrey - 11/21/2008

Question
I have a room addition that is 20'x 20', The room is open (no interior walls) It has 2x8 rafters and a 2x10 ridge pole. The roof pitch is about a 4-12 pitch. The ceiling has dropped about 4'' and the side walls are pushed out about 2''. I have raised the roof and pulled the walls in over a five day period. I am going to install ceiling collar ties but do not know were to posision them. the run for the ceiling is about 12'(cothedral ceiling). The collar ties will be 2x6 cedar that will be exposed.
Thanks Jeff

Answer
Jeff,

Good job getting that straightened out! That's hard to do sometimes, after the wood has taken a set.

Usually, when the walls push out, it means the ridge has sagged. Conversely, if the rafters sag and the ridge holds, the walls come in.

Put the collar ties as far down as you can. This usually means somewhere in the lowest third of the rafter. For a 4/12 pitch this means pretty much that your collar ties need to be somewhere around 14 to 16 feet minimum. This will put the strain back onto the rafters, instead of the ridge.

Good luck!

Daniel