I want to convert my cottage roof to a cathedral ceiling. It is presently a 5/12 pitch with rafters made from 2x6 16" on center. I will be installing collar ties on each rafter and a 4x6 beam every four feet. To make room for insulation and an air-gap I want to add a 2x4 on edge to each 2x6 rafter installed from the inside for a total of 9". What is the best way to fasten the 2x4 to the 2x6 on edge?
Answer:
I think using quarter-inch fir plywood, good one side on each side of the rafters (full depth) would do it provided you use screws and glue rather than just nails. You can trim up the bottom with 1X3 stock fir for the sake of aesthetics and continuity.
