I am adding a room on to my house. The new room will be using truss, but the truss will only go to the old load bearing wall, which is where the new room starts. The slope of the new roof is such that the rafters off the new truss will intersect on the old roof about half way up the old roof. My question is how do I tie these rafters into my old roof? Do i attach to the old roof sheating or cut the sheating off and attach to the old roof rafters(which are really trusses themselves)