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Community and Q&A

Homasote in Service Cavity for Added Insulation and Sound Barrier

jlkue | Posted in Energy Efficiency and Durability on

I added 2” of rigid foam to the inside of my attic for a sound barrier and for another r-10. I’ve added furring strips in front of the foam to hold the Sheetrock and saw an image somewhere about optional insulation in the service cavity. Would 1/2” Homasote between the furring strips do anything for me regarding sound and insulation? Or is it a waste of time and money. (I’m in zone 5a)

Attached image shows Homasote installation test.

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  1. Expert Member
    BILL WICHERS | | #1

    What type of sound are you trying to block that is coming from your attic?

    My guess is the homesote board won’t help much. There are probably other options that will work better, but it depends what you’re trying to do. Blocking footsteps on a floor is different than blocking noise from airplanes flying overhead, for example.


  2. jlkue | | #2

    Thanks Bill,

    It's my office now and I'm trying to soften outside noises like kids shooting hoops against the house and also prevent more sound going out from things like phone calls or even movies in the evening. Footsteps aren't an issue as its a garage below.

    Mostly though, it seems like in a small space, something could be done with the 5/8" service cavity instead of just leaving it filled with air? Maybe it's good enough and there's no thin insulation to add (to help with sound and insulation).

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