Added some windows to my in-laws’ basic T1-11 detached garage. Next comes electrical. Then insulation/drywall.
Walls are 2×4, we’re in CA so R-13 should do it. This is just to make the space more comfortable overall. There is no heat or AC.
Cieling joists are 2×4 trusses -24″ OC. How would insulate these? 22.5″ bats between the trusses? Or lay the insulation across the trusses, thus eliminating heat bridging?
And since the trusses don’t appear to have been engineered for storage, the attic space is pretty useless. But is it SOP to frame in an attic access, even if it’s a 2′ x 2′ panel? I think drop down stairs are out of the question, if not only because they’re just more money. What do the experts do? Yes, I mean you guys 😉
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I'm not exactly an expert, but you can lay insulation between the joists and then lay more insulation batts crossing over them (perpendicular)--depends on what r-value you want. Even in California, a litle extra in the ceiling would be good--may even keep it cooler in summer.
Kraft-faced batt insulation in rolls, complete with staple tabs, are made for your between-the-trusses application.
Choose your R, load the staple gun, and do it.
Roof/attic vents are a must.
Attach wires 2'OC across the bottom of the ceiling joists/trusses.
Lay in foil backed bats, foil to roof.
Drywall ceiling.
Yes to access.
In my opinion more than 3 1/2" bats in an unconditioned Calif garage is a waste of money. I wouldn't even insulate the north or east sides below 4000' elevation in CA.
Uhhh. . .Unless you're in the Imperial Valley, then I'ld use R-90 on all surfaces and install a 50Ton AC unit (|:>)
For the ceiling - I'd drywall it then blow in insulation. Blown is cheaper than batts.
Definitely add an access hole. Beats cutting one in later when you need to do wiring or whatever. You never know what they may want down the road.
Thanks to all. I was going to use R-30, but sounds like that would be overkill. I'll start framing an access today.
Maybe 2' x 3' with plywood that drops down flush to the cieling drywall and some sort of casing around the opening.