Soundproof Insulation for Walls: The Best Materials to Get

Sound insulation is one of the most effective soundproofing methods you can use in your walls and ceiling.

But how does sound insulation work? Why do you need it?

Also, there are a lot of soundproofing insulation materials to choose from. Which one is best for you?

In this article, we will cover the topic of soundproof insulation for walls and the best materials to get. You would also learn the basics of insulation and its installation.
Mikkel Holm, Founder of TheDIYClub.com

Here we go!

The basics of insulation

If you could take a look at the insides of your wall, you would notice that there are two solid layers with an empty space in between.

That empty space is where you place the insulation. You’ll have to close that space inside the wall to minimize the sound waves that pass through.
Mikkel Holm, Founder of TheDIYClub.com

Insulation materials are usually installed to keep the house warm in winter or cold during summer. The fibrous component of the insulation material traps the hot air that passes through.

Soundwaves usually travel by air though they could also travel through solid objects like in the case of impact sound. So the same component that keeps a house warm or cold also traps the soundwaves that travel through the air.

Basically, there are 3 types of insulation materials:

  • Batt insulation – they are rectangular panels or rolls usually made of fiberglass, cotton, or mineral wool used in insulating walls
  • Foam spray insulation – these are liquid polyurethane sprays that expand to fill the space on the wall
  • Blown insulation – similar to batt insulation used in insulating attics but the materials are blown to pieces to fill the space

Out of the three, batt insulation is the most effective when it comes to soundproofing. Blown insulation clearly can’t do much soundproofing.

Rockwool (Roxul) Mineral Wool Insulation

When it comes to insulation materials, Rockwool (rebrand from Roxul) is one of the most popular brands out there.

roxul rockwool acoustic mineral wool

Mineral wool insulation materials from Rockwool are of the premium quality. They have water-repelling qualities with a Class A fire rating. In terms of soundproofing, they have a very high NRC (Noise Reduction Coefficient) rating.

These materials are sold in a bundle with 12 panels per case. Different thickness has different prices.
Mikkel Holm, Founder of TheDIYClub.com

Features:

  • High NRC rating
  • Class A fire rating
  • Comes in 48” x 24” x 1”, 48” x 24” x 2”, 48” x 24” x 4” sizes
  • Price range: $50-$76
  • Source: Amazon

Owens Corning Fiberglass Board

Insulation materials from Owens Corning are the closest alternative to Rockwool products.

owens corning fiberglass board insulation material

Owens Corning insulation boards come in 2 variants: 703 and 705. Whichever you choose, they are all lightweight, resilient, and easy to handle and install.

The boards are made of inorganic glass fibers with thermosetting resin binder formed into rectangular panels.

Aside from basic qualities you could expect from a quality insulation material, these boards can also resist short durations of water exposure.
Mikkel Holm, Founder of TheDIYClub.com

Features:

  • Reduce heat transfer
  • Limited resistance to water
  • Comes in 48” x 24” x 1” and 48” x 24” x 2” sizes
  • Price range: $65-$130
  • Source: Amazon

ATS Acoustics Rigid Fiberglass Board

ATS Acoustics creates different acoustic panels as well as acoustic art panels. However, they also seem to be a distributor of some of Rockwool and Owens Corning fiberglass insulation materials.

But rest assured, they have their own brand of acoustic rigid fiberglass board.

ats acoustics rigid fiberglass board
These boards come in a case of 6 pieces. Their fiberglass material is cheaper than that of Owens Corning making their products the exact substitute.
Mikkel Holm, Founder of TheDIYClub.com

In terms of difference, ATS Acoustics insulation boards are slighter lighter in color and softer than Owen Corning’s 703 variant.

The materials are also covered in fabric so you can use them to mount on walls instead of putting it inside.

Features:

  • Cheaper than Owen Corning
  • Similar in quality to Owen Corning
  • Comes in 48” x 24” x 1” and 48” x 24” x 2”
  • Price range: $55-$76
  • Source: Amazon

Dow Spray Foam Insulation Kit

The Dow Froth Pak is an excellent spray foam insulation kit that helps insulate wall cavities up to 2 inches thick.

This spray insulation foam material from Dow is a quick-cure polyurethane foam that fills cavities, cracks, and expansion joints — perfect for insulation and air sealing.

At the same time, Dow’s product also reduces the potential for moisture, mold, mildew, allergens, and rot. Plus, a single kit yields up to 650 board feet of foam which are Class A fire rating.
Mikkel Holm, Founder of TheDIYClub.com

Features:

  • Yields 650 board feet
  • Class A fire rating
  • Price range: $300-$800
  • Source: Amazon

Convenience Products Touch N Seal

Touch N Seal is a quick-fix spray closed-cell foam insulation kit which is a good alternative for Dow Froth Pak.

This product yields 15 board feet with a quick consistent flow of foam that dries in a minute. The foam expands up to 30x designed for commercial sealing, insulating, patching, and filling applications.
Mikkel Holm, Founder of TheDIYClub.com

The high closed-cell content of polyurethane foam makes Touch N Seal suitable as a quick-fix sealant to prevent air leakage. With reduced air leakage comes reduced sound waves.

Features:

  • Yields 15 board feet
  • Dries within 1 minute
  • No CFCs or urea-formaldehyde
  • Price range: $50-$55
  • Source: Amazon

Installation of insulation materials on the walls

Expectedly, the installation of insulation materials on your wall would require construction.

If you’re renting, make sure to talk to the owner first before making any changes.
Mikkel Holm, Founder of TheDIYClub.com

Here are things you should remember when installing insulating materials on your wall:

  • Make sure to clear the wall.
  • After removing the drywall, don’t forget to measure the height of the wall and the width between the studs.
  • Also, take note of how many hollow slots there is.
  • Cover yourself with old clothing, masks, and goggles since the materials can irritate parts of your body.
  • Make sure to push the material inside to fill out the entire space.
  • You can use acoustic caulk to cover the gaps or spaces if you see any between the insulation material and the stud.

Wrapping things up…

In choosing the best insulation material, consider first your budget and which type you would like. If soundproofing is your main concern, choose batt insulation materials. Once you got it right, you can expect a boost in the wall’s soundproofing.

Insulation is an effective way to soundproof your room by making sure there are fewer soundwaves that come in through the gaps inside the walls.

Mikkel Holm, Founder of TheDIYClub.com