I have a 20×10 cabin by our pond made of landscape timbers. I plan on really fixing it up inside, it has a full electrical panel in it. I want to put 1/4 log end matched t&g siding over interior walls on ends and knotty pine t&g planks over walls and ceiling. Question, how do i insulate and do i need vapor barrier? Do i need to vent such a small room at ceiling, has cedar shingles. Thanks!!