Q: What’s the best way to insulate over an exposed 2x6 tongue-and-groove cathedral ceiling on a log house in Colorado? Some have suggested using SIPs, but others have advised that, because this particular roof is cut up with valleys and dormers, I would lose the labor savings associated with SIPs and end up with a very expensive roof. Another suggestion was to box out the roof with 2-bys, then spray foam insulation into the grid and cover it with plywood. A final suggestion was to put down foam panels right over the 2x6 plank ceiling, seal the joints, and lay plywood over that. Unfortunately, no one has given me details for these applications. Can you advise?