I have a roof about 50 years old with a 4:12 pitch and 2X4 common rafters. The problem is at the half way point between the ridge and the top plate on the wall there is about 3/4 of sag. (About 11 feet from ridge to the birdsmouth.)
What is the best way to take the sag out of these rafters? I worry that if I were to attempt to run a brace to the ceiling joist that this would in effect push the ceiling down.
Any ideas?