View Full Version : Insulation in ceiling between bathrooms?

07-19-2011, 04:59 PM
I'm remodeling the bathrooms in my 2 story home. Two bathrooms are directly above the 1st floor bathroom. Now that the drywall is down, I'd like to add some rock wool insulation, Roxul R15, in the ceiling of the lower bathroom. This is not so much for thermal benefit as it is for sound deadening between the bathrooms. I'd like to soften the noise. I know I can't sound proof it completely without tremendous effort and expense. So, softening the noise is all I want. Roxul makes Safe n Sound, but that would be more than I want to spend. The R15 comfort batt seems to muffle the noise in the other parts of the home.

The 1st floor bathroom ceiling is 7' high due to all the overhead plumbing. The original builder constructed a 2 x 4 frame 7' x 5' to hold the ceiling board. I plan to use 1/2" ceiling board (no sag type).

Does anyone see any problem with this application? Would adding the insualtion be a mistake should there be a leak from above?


07-20-2011, 05:26 AM
It'll be fine. Both products work well. The S&S is a little more dense, but is also a bit thinner. I used both products throughout my basement remodel (S&S in the ceiling and some interior walls, R15 on exterior walls). Too bad you aren't closer...I have 2 bags of S&S and 1 bag of R15 left over that you could have used.

Around here, I had to special order the stuff. I even called some places around that were supposed to "stock it" based on the Roxul website and the places acted like I had two heads or something. :) I finally had to order through HD, but they even had no idea that they could get it and I had to provide the vendor, SKU, etc. to get them to find it/order it.

07-20-2011, 10:33 AM
Hi Nukeman,
Thanks for the offer. I just finished the installation of the R15 and had just the right amount. Roxul told me that I could mix the leftovers in my attic along with the other insulation, that it would just improve the situation. Not a bad idea. Roxul is pretty good stuff, but not cheap. I insulated every interior wall where the drywall was removed. I've noticed some improvement in the soundproofing. It's not completely silent, but there is improvement.

07-20-2011, 01:08 PM
It does help..especially with higher frequency sounds.

Around here, it wasn't too expensive. Sure, it is close to 2x the cost of basic R13 fiberglass, but it is less than the R15 fiberglass. I like the way it cuts and the friction fit. Also, since I was using XPS before the studs, I wanted something without a vapor barrier and it is hard to find unfaced R13/R15 fiberglass around here.

Overall, I am quite happy with it. The inspector was also surprised to see it. He knew of it from helping someone soundproof a music studio and had also seen it used in some commercial situations, but was really surprised to see it in a residential setting.

07-21-2011, 06:04 AM
Roxul Safe and Sound is very common here in Vancouver. Pretty much every yard stock it and the box stores. I used it in my home's interior walls and it does and amazing job of deadening the sound of the kids....

No so much the jumping and running - but the sounds like whining and screaming are reduced to manageable levels. I have even slept in twice in the last six months and this never happen before with the old house. Too much noise...