I'm just not sold on closed cell insulation in the attic/roof deck or walls. I've heard of too many issues.

I am open to open cell in the attic/roof deck, or radiant barrier. I don't believe I want spray foam in my walls --- just in the event that I ever need to access a wall in the future with electrical, low voltage wire, etc.

That said, I am considering rock wool or cellulose. From what I have read, blown in cellulose will fill in the gaps better, whereas rock wool is in roll or batts. Rock wool is supposed to be better at sound proofing, whereas air leakage, cellulose wins.

I read that if rock wool is installed correctly, it can achieve the same or slightly better R-Value that cellulose does.

What is the board's thoughts on this? Or should I be looking at something entirely different?

This post was edited on 3/9/26 at 8:54 pm

3 ...

Report Post

Posted by Civildawg

Member since May 2012

10467 posts

Posted on 3/9/26 at 9:15 pm to Will Cover

Rock wool on walls and cellulose on attic deck

0 ...

Report Post

Posted by LemmyLives

Texas

Member since Mar 2019

15445 posts

Posted on 3/9/26 at 10:46 pm to Will Cover

Are you mixing problems that are solved via different methods?

You're in NC, not Houston, but tinting my windows for under $2k cut my electric by hundreds of dollars a month in the summer immediately (already had radiant barrier in the attic.)

I don't think you can truly soundproof anything that isn't a SCIF. Vibrations are always going to propagate through the frame, floors, etc.

2 ...

Report Post

Posted by Will Cover

Davidson, NC

Member since Mar 2007

40157 posts

Posted on 3/10/26 at 7:05 am to LemmyLives

quote:
You're in NC, not Houston, but tinting my windows f

I'm actually in Louisiana (disregard the location you see on here).

quote:
I don't think you can truly soundproof anything that isn't a SCIF. Vibrations are always going to propagate through the frame, floors, etc.

I should clarify. I am trying to decide on rock wool or blown in cellulose for exterior walls --- and interior walls. I am not expecting full sound proof, but I certainly want something in between my interior walls to help with reducing sound significantly rather than just two pieces of drywall. I am also going to be looking at solid wood doors as well.

2 ...

Report Post

Posted by easy1234

Baton Rouge

Member since Oct 2010

268 posts

Posted on 3/10/26 at 7:10 am to Will Cover

I did Rock wool in wall, already had R-25 in attic put up radiant barrier. Works Great

0 ...

Report Post

Posted by SETH6180

TEXAS

Member since Feb 2020

1081 posts

Posted on 3/10/26 at 8:01 am to LemmyLives

Lemmy, who'd you get in Houston to do this for you?

0 ...

Report Post

Posted by Mmackl1

Member since May 2011

245 posts

Posted on 3/10/26 at 8:33 am to Will Cover

Staggered stud walls for soundproofing areas with insulation (2x6 bottom plate with 2x4 studs)

shoot me email …username at yahoo. I’ll send you pics and some performance from one I just finished with this.

0 ...

Report Post

Posted by Supermoto Tiger

Baton Rouge

Member since Dec 2010

10668 posts

Posted on 3/11/26 at 10:19 am to Will Cover

For 3 1/2" walls, I would choose Rockwool R15 as opposed to cellulose and if 6" walls exist, use the R21. It is available both in batts or you have have it blown. i would also use the R38 in the ceilings.

Also, use an acoustical caulk at the bottom and top plate and around any outlets to provide a better sound solution.

Page 1