Hello there
Kindly advice here.
My new home is under construction in Huntersville, NC. Builder said they will insulate outer walls but not inner walls. I like to insulate inner walls for reducing noise from adjacent rooms. I like to insulate all inner walls with R13 or R15 (2×4) such as wall between living room and bedroom, wall between living room and laundry area, wall between kitchen and dining room, wall between two adjacent bedrooms, wall between bedroom and bathroom, etc. I am wondering if i need to use faced or unfaced insulation here. If i use unfaced insulation, will there be any water vapor issues? Â Do i need to put vapor barrier sheet? And which side vapor barrier should face? i. towards living room or towards bedroom side? Or can i install vapor barrier on both sides of the wall? Or is it good not to install vapor barrier at all but install unfaced insulation only?
or do not insulate at all? Please advice what is right thing to do here to avoid damaze to the home. Thanks much
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unfaced Rock wool is good to use for such an application. (better sound properties than fiberglass.) They sell batts sized for standard stud types and spacing, and options for batts thinner than you would use for exterior walls.
there would not be a need for a vapor barrier on these internal walls.
Vapor barrier (vapor control) are called for when there is a large difference in temperature across the wall, and potential for condensation inside the wall as warm, moist air meets a surface below its dew point. This should not happen within the heating/cooling envelope of the house.
Hello Mike
Thank you very much for the info.
I hope you are referring to one of these below. Can you please suggest me the right one? Thanks. Please feel free to share any other links.
https://www.lowes.com/pd/ROCKWOOL-SAFE-n-SOUND-R-Stone-Wool-Batt-Insulation-with-Sound-Barrier-15-25-in-W-x-47-in-L/3394032
https://www.lowes.com/pd/ROCKWOOL-COMFORTBATT-R-15-Stone-Wool-Batt-Insulation-with-Sound-Barrier-15-25-in-W-x-47-in-L/3388304
Sound isolation involves a lot more than insulation in walls. You need to caulk the bottom plate to the floor with noiseproofing caulk. add mass to the ceiling, use a soft floor covering and solid core doors with thresholds. Stopping sound is about mass and while rock wool is better than nothing a poorly fitting door will let the sound through anyway. Another layer of drywall on each side of the wall is your best bet for low-cost semi-soundproofing.
I agree with Florida, but I want to make the point that Rockwool will still be better than regular fiberglass and definitely better than nothing.
It's still worthwhile doing!
Thanks Steve. I was expecting the same. Hope it helps reduce the sound transmission.
Thanks Florida. Seems lot of work to do.