My newly enclosed 400 sq ft garage will need insulation. I was going to get R13 batts and R38 batts for the walls and ceilings (2x4 walls). However, a contractor and craigslist has a lot of insulation overstock for a hell of a price (12 bucks for a 30 lb bag). He has a bunch of the blown in stuff. I could rent the machine for a day and do all the blown in and use cellulose which has a higher R value than fiberglass. I would have to cut holes in the walls, not a big deal, for hose access. However for the ceiling, that seems tricky for me. My ceiling joists aren't flat (meaning parallel to the floor). They're sloped at a similar angle to the pitched roof. Would the blown in stuff settle and slowly slide down leaving the apex as a warm air leak? Granted that's like 18 feet above my head, but it's still a loss of energy.
Insulation for the garage
- Thread starter mendozer
- Start date
ambenz
Well-known member
For the ceiling you could use old cotton sheets or rolls of cheap burlap to contain the insulation. I would staple baffles every few feet to contain cells so the insulation doesn't fall over time. Check out a fabric store for ends and discontinued linen bats...heck you could even make big pillow covers.
So you mean use fabric to essentially make a "sack" of cellulose? how would I do it at the very top of the apex?
the guy ran out of the blow in stuff. He still has batting, so I might get some R38 from him then. And I was going to put 1/2 OSB up as it's the same I'm using for walls. I'm trying to source a propane radiant heater too since I have propane right outside at the water heater. Run some piping in there and bam, no longer have to wire and install expensive electric radiant heater elements.
Wileel
Well-known member
I'm curious if your wall and ceiling are bare now why it the OSB your choice?
Insulation contractors do this all the time. They staple up reinforced plastic and leave a "hatch" to stand in and blow the insulation. When they are done they staple it mostly closed and shove the hose in through the slit to fill in the last bit of insulation.
You could also hang most of the sheets of OSB on the ceiling. Then they could blow insulation above that and just net the last little bit.
Simple. Cost and paintability. I can get them for 7.50 a sheet and if I paint them ( which I probably will for the ceiling maybe not for walls) they take paint very well and don't have holes like plywood. And I don't care to put up drywall
But also I like the stranded look more than cheap plywood. I could put nice veneered plywood which is nicer but then that's expense for no reason other than looks
I understand now. I watched videos on this. Since he ran out that's no longer an option but good to know. His r30 Batts are going to cost a lot less than the 25 or so bags if need for blown in
Wileel
Well-known member
So even though that guy ran out I just looked and The Depot has blown cellulose for 11.80/bag for one type (all borate, but it doesn't matter to me). And while that's a couple bucks more per bag, if you buy 20 bags, the machine rental is free. So 25 bags would be $300. Whereas the batting would cost me $135 for 3 bags of the R13 and $275 for the R38 6 bags. So it's cheaper to buy it new, and I'm assuming faster. Both methods need sheathing but I'm already cringing at installing batting overhead on a 15 foot ladder. For blown I just cut out holes in the tops of the OSB for walls and either shoot it over the sheathing for the ceiling or make batts. I was reading on the downsides of vapor barriers, especially in garages so I may not do that, unless I used a membrane type fabric and not poly. But then that's extra cost so I'd rather just shoot it over. And hell if it's cheaper I could shoot a few more bags up there for good measure.
So now...it's a tossup. I'm liking what I'm reading about cellulose vs fiberglass. Any other opinions to chime in on?
So now...it's a tossup. I'm liking what I'm reading about cellulose vs fiberglass. Any other opinions to chime in on?
First quote I got was 1700 + tax. No thanks. I will do this myself. One thing Im curious about is the best way to get this front part. The joist angle doesn't match, so i'll need a board up there for sure, but I want to get the whole thing insulated. On the house side it's easier because I just nail up a 2x4 to take the sheathing and call it good. This will require some creativity.
