How much additional noise reduction can I get by combining Rockwool sound insulation with QuietRock drywall? Or does one render the other moot?

I'm looking to add some noise reduction to an unfinished garage workshop with a goal of lessening the noise from my power tools. Those were the two products I came across that seem to be readily available for DIYers.

I've realized sound proofing is a complex topic and there are a ton of variables to consider (stud spacing, doors, windows, sealing, etc. etc. etc). My goal is to make incremental improvements towards noise reduction and to disturb my neighbors less whilst enjoying my woodworking hobby more.


  • "Is it worth it" is an opinion based question. It may be to some it may not be to others, and, therefore as worded this could easily be closed. Edit your question to ask "how much additional noise attenuation will I get if..." and someone should be able to get you some empirical numbers instead of opinions. Then you can determine if it's "worth it".
    – FreeMan
    Mar 1, 2021 at 18:23
  • Is the garage attached or detached? Are you just trying to shield the house inhabitants from the noise or also the neighborhood? Are you interested in also insulating your garage door?
    – MonkeyZeus
    Mar 1, 2021 at 18:26
  • Anyways, have a read at bettersoundproofing.com/best-soundproofing-insulation
    – MonkeyZeus
    Mar 1, 2021 at 18:29
  • @MonkeyZeus The garage is detached, but there's only about 4 feet of space between the structures on either side. I'm mostly interested in shielding the neighborhood. Yes, I would also like to insulate the garage.
    – Anthony
    Mar 1, 2021 at 18:47
  • Something is always better than nothing. The rockwool and quiet rock combination should work fine and will be better than just doing one instead of the other; you need to look at their ratings such as STC or NRC. If you want perfection then consider making your garage look like this after the walls go up: soundproofingtips.com/wp-content/uploads/2018/06/…
    – MonkeyZeus
    Mar 1, 2021 at 18:50

1 Answer 1


As you have noted too, sound proofing is a complex topic. Some published success stories are based on questionable data, others are based on specific cases, typically a basement / home theatre, or maybe a music room.

Sound proofing is expensive in terms of labour and materials, making it difficult to attempt by trial and error.

If your case falls clearly within the conditions for established practices, then those practices are your best bet.

I have found that rockwool provides mostly attenuation along its length and less laterally. It's great for stopping noise travel in joist spaces and other boxes, but less effective through it's mere 3 inches of thickness. Despite these reservations, stopping noise travel has an overall benefit, even in a wall, as noise entered at a weak spot in the wall (crack, outlet box, coupled vibration) does not travel to exit at another weak spot in the wall into an adjacent room. However, this is not your use case.

Your use case involves mostly higher frequencies, not drum-thumps or foot drops, and they emanate from any wall or window into the open.

Luckily higher frequencies are much easier absorbed or reflected.

If your intent is to sound proof an isolated out-building (garage) for the benefit of the neighbourhood whilst enjoying woodworking, there are a few easy steps you can take:

  1. Make sure your inside walls are solid (crack & gap free) and heavy on the inside (e.g. double 5/8 drywall, mudded and sealed). This contains the sound by reflection.

  2. Apply absorbing materials to the inside of the noisy space: it absorbs the sound as it reflects off surfaces, and will reduce the amount of high frequency noise emanating from the garage, no matter where the absorption is placed. You can even apply noise absorbing pads to the ceiling where it is least likely to collect saw dust. Best to use fire-retardant materials or pads.

The additional benefit of the inside-absorption approach is that any small exhausts or other small venting passages are no longer critical elements in the sound proofing.

It also makes for a more pleasant working space.

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