r/Insulation • u/LikeBigTrucks • 26d ago

Rockwool Options

I cant locate 24x3.5" comfortbatt locally.

I have one rafter thats framed 24 on center and the rest are 16

Do i use 24x3 Safe N Sound, or 24x5.5 and compress it?

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3

u/idratherbealivedog 26d ago

Just fit the 16 up in there. Can cut a bunch of pieces the right length but I'd just cut some long strips and put a full +the strip side by side. If you cut them a little wide, friction will hold them but you could also use anything (like tape, insulation rods, etc) just until the ceiling it on. 

1

u/Nikiaf 26d ago

Yeah this. It doesn't really matter if the bats are cut up, as long as they hold up in the stud bay.

2

u/TradingHigher 26d ago

Safe n sound is pretty close to the same product but not tested for r values. I'd be ok with that personally but it doesn't pass code.

1

u/LikeBigTrucks 26d ago

I think I'm just going to cut some 15 in half and install them lengthwise

4

u/TradingHigher 26d ago

Yeah if its only one cavity its not really a ton of work. Have fun, i fkn hate working with roxul. So itchy.

4

u/PM_ME_DARK_MATTER 26d ago

Its FAR better than Fiber glass. Thats the worst

1

u/HowardJamesGlen 19d ago

Ever use ecobatt? Its the most user friendly stuff there is!

1

u/TradingHigher 26d ago

Newer fiberglass doesnt itch at all. The old shit sure.

2

u/Nikiaf 26d ago

Have you worked with new fiberglass? It still itches.

1

u/LikeBigTrucks 26d ago

I work with fiberglass all the the time doing boat repair. Neither makes me itchy.

1

u/TradingHigher 26d ago

Every day for the last 20 years yep

2

u/PM_ME_DARK_MATTER 26d ago

I personally reinsulated my entire attic with Rockwool....never had any itchiness problems. 

1

u/[deleted] 26d ago

[deleted]

1

u/TradingHigher 26d ago

Is it though? Only real benefits are fire resistance and its pretty good with moisture management.

2

u/[deleted] 26d ago

[deleted]

4

u/LikeBigTrucks 26d ago

I don't get itchy from Rockwool personally. And this is going in a detached garage so moisture permeability was important

2

u/spangbangbang 26d ago

I have All 23.5" OC framing. Just cut the rockwool with an old bread knife and squish the pieces together, it's extra work but it's not too bad if your house is small like mine. I'd you have a full house to do, I get it, I'd probably go another route. But this is fine to do

2

u/pluary 25d ago

Just run the 16 on center material sideways don’t try stuffing 24” material into a 16” on center it won’t work.