2

This is my basement ceiling this morning:

enter image description here

After a couple of hours, I removed all drop ceiling for entire basement with 1 living room and 2 bedrooms:

enter image description here

I would like to install drywall with access panels near plumbing and most IMPORTANT: Soundproofing.

I searched online and there are many ideas but I cannot decide which idea to go for. I want to achieve two purposes: (1) block from air travel and (2) block from floor transmit (vibration from someone walking on top). One issue is that I cannot do anything about the wall because it is just too much work. So the focus is the ceiling only.

So my options that I researched are:

  1. Use regular R30 insulation and drywall. This seems cheapest but does it work OK most of the time for soundproof?

  2. Use Acoustic Insulation Roll. But I don't know how to install this. Is it "wrapped" around the joist and basement ceiling plywood then install drywall below? Or it is sandwiched between two pieces of drywall?

enter image description here

  1. Use Resilient Sound Isolation Clip for drywall

  2. Use specialize product with both insulation and Resilient Channels

enter image description here

I would love to hear more advise and past experiences from everyone.

Thanks.

  • Mass is key in reducing sound transmission, so closed-cell spray and rockwool would be better than fiberglass. Sorry I can't answer fully. Soundproofing isn't my specialty. – Hari Ganti Sep 4 '18 at 21:42
2
+50

I've been interested in this topic for years, but 'back in the day' there wasn't much info on the 'net about it.

Jacks post about RC1 made some sense, so I took a deeper look and found that while on the surface it may seem that he was correct, the use of RC-1 is not recommended by the Steel Stud Manufacturers Association (SSMA) and it's lack of industry standard or specification for its construction is concerning.

To sound proof a room you need to do 4 things:

  1. Decouple The Framing
  2. Install Absorption in the Cavities (Insulate)
  3. Add Mass (Drywall)
  4. Add Damping

Decouppling

The best sound isolation comes from a double stud wall with green glue. But, installing staggered studs to hang your drywall should be more effective than direct attachment to RC channel.

Most effective ways to isolate sound

enter image description here

For a ceiling, you likely don't want the reduction in ceiling height and increase of cost of double studs. Thus a staggered-stud, or sound proofing clips with furring channel is likely your best path forward. According to the SSMA, to use soundproofing clips you should hang 7/8” Drywall Furring Channel aka hat channel (not to be mistaken with RC-2) from the soundproofing clips at a 48" span. RC-1 as well as RC-2 won't fit inside RC clips.

enter image description here

Insulation

While foam (open or closed cell) is superior for thermal it is distinctly worse for acoustic, just use the cheapest R13 for the walls, and R19 in the ceiling you can find.

Adding mass (Drywall, Plywood, OSB, and Cement Board)

For sound to conduct through a wall, it has to actually move the wall ever so slightly . A heavy wall is harder to move than a lighter wall. Standard 5/8” Type X is best as it is 70+ pounds a board, and cheap at $7 a sheet. Use two layers. Only mud and tape the final layer. Adding more than 2 layers doesn't improve things much, especially in the bass range: enter image description here

Damping

There are many field applied damping compounds such as green glue that translate the vibrational force laterally converting the sound into heat. If we prevent the drywall from vibrating, the mass, insulation and decoupling become are more effective:

enter image description here

  • 1
    Excellent explanation. Don’t forget to caulk perimeter of ceiling, use as few openings (ceiling light box) as possible and box in around all openings. – Lee Sam Sep 5 '18 at 4:15
1

RC-1 channel will be the best bang for the buck install for sound control. If I remember properly it reduces sound by 20 db on it's own. The drywall installers will absolutely have to screw the drywall only to the RC channel and not through to the joists, it defeats the purpose. Fiberglass batts will help too. The sound roll, from my experience is very costly, but if you use it, it would be attached to the joists, not wrapped, set flat and the RC channel would go over the roll.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.