Question about insulation

[biggziff]

I'm leaning towards just buying fiberglass batts to speed up my insulating work in the new shop. I'll use the 48" faced R-30 batts I think. Someone about an hour from me has 40 packs of the JM stuff (yes, I know it'll be compressed slightly in a 2X6 wall) and Lowes/HD has the Pink stuff. It all seems about the same to me, but what do I know?

Is there any actual difference between the 2 linked below?

https://www.lowes.com/pd/Owens-Corn...th-Sound-Barrier-16-in-W-x-48-in-L/1000504265

or

https://www.homedepot.com/p/Johns-M...sulation-Batt-15-5-in-x-48-in-K1264/206116299

 

[mm08822]

Be careful using r30 in a 2×6 wall. Fiberglas insulation has been known to pop drywall off the wall.

Consider r21 if using drywall. It's a non-issue with plywood however.

 

[biggziff]

Be careful using r30 in a 2×6 wall. Fiberglas insulation has been known to pop drywall off the wall.

Consider r21 if using drywall. It's a non-issue with plywood however.

No kidding? Fluffy fiberglass can pop 5/8 dry wall?

 

[acer66]

It says it is 9.5” thick, how will you fit that in a 2x6 wall and why would you want to do that?

 

[biggziff]

It says it is 9.5” thick, how will you fit that in a 2x6 wall and why would you want to do that?

I'd use the 8.25" R30C. Compressed it will end up around R22-R24 which is higher than the 5.5" thick R21. R30C is cheaper per package so I spend less and end up with a higher R value.

 

[mm08822]

No kidding? Fluffy fiberglass can pop 5/8 dry wall?

yes, I used to work for OCF and recall several times customer complaints about this very problem. A few times it was out of spec fiberglass (denser)but nobody cares about that when walls were popping.
I can't tell you drywall thickness or # screws/nails used for those instances, but it's a real problem.

It's not so "fluffy" when you don't let it recover to specified height. And you won't get the full stated r-value in that condition.

Buy extra drywall screws if you head this way.

 

[biggziff]

Interesting that HD says this stuff is for 2X6 walls. 9.5" thick. Obviously, not the best choice.

https://www.homedepot.com/p/Owens-C...ation-Batt-16-in-x-48-in-8-Bags-A18/205469829

 

[acer66]

I'd use the 8.25" R30C. Compressed it will end up around R22-R24 which is higher than the 5.5" thick R21. R30C is cheaper per package so I spend less and end up with a higher R value.

Interesting, do you have a link with a test about the r value change when compressed?

 

[biggziff]

Interesting, do you have a link with a test about the r value change when compressed?

I just googled "compress insulation" Lots of returns.

 

[850xpeps]

Don’t compress the insulation. Buy the proper stuff. It will pop drywall screws if there’s too much pressure.