Mike writes from Middlebury, Connecticut: "I have a Greek Revival farmhouse built in 1850. I have removed to floor and ceiling joist in the attic of part of the house and am converting the ceiling to a cathedral ceiling. The roof rafters are trus 2" X 4". We are going to put in a few more rafters for added strength. Is there a system where I can hang R-38 or higher insulation and also attach the ceiling drywall or do I have to put in all new 2" X 10" rafters?"

Also, I have removed all of the plaster and lath so the walls are exposed. The plan is to put in R-15 between the true 2" X 4" studs and cover it with 5/8" drywall using vapor barrier paint. We plan on leaving the old 7/8" sheathing and covering it with 1/2" plywood, 1/2" rigid insulation, housewrap and 1/2" clear vertical grain redwood siding.

After 160 years the old sheathing and studs are in good condition because there was no insulation and moisture could escape. I am concerned that I might trap moisture. Do you think this design is OK?

Answer: For the cathedral ceiling you will need to build the rafters out to 2 x 10. I am not aware of any system like the one you are looking for.

I do not see any problems with the assembly but remember that I am an actor and not an architect or designer. My friends at Owens Corning are insulation manufacturers and not the people to judge assemblies.