Insulating a garage
I have a 21' x 21' area garage with 8' of vertical wall until the roof pitches at a 45 degree to the peak. I am looking to insulate it to keep it warm in the winter, and cooler in the summer. Should I be insulating up the pitched roofline and drywalling, or should I add beams across the garage and insulate it from the top down like an interior flat ceiling?
Also, if I need to add beams to go across the entire 21 feet, will I need lolly columns in the middle to support those beams at about 11.5 feet or will I be ok?
Re: Insulating a garage
If it were my garage, I'd just insulate the walls and go right up the rafters. I like attic space in garages, for storage of things. I wouldn't want to cover it up in mine. Some new houses HAVE to cover up the ceiling before getting a Certificate of Occupancy but I doubt you've got that problem.
Running ceiling joists and drywall is going to cost you some money. With that much of a span, you'll have to use some substantial material (like 2x10 at least). Expensive. I'd support the joists in the middle with a 4x beam and a couple of posts in the middle of the garage, separating the two sides.