Brick walls and soundproofing (what you need to know)

Brick walls are good for soundproofing, as they have a naturally high mass to reflect airborne noises. However, not every brick is made equal and not every brick wall will be good for soundproofing. We will go through what makes a brick wall soundproof and how you can improve yours.

Can you hear through brick walls?

Yes, you can hear through brick walls if the sound is very loud, or, if the wall has weaknesses to noise. Weaknesses include not being double-skinned (two layers of brick), back-to-back electric sockets, and unfilled cavities. While bricks have a high mass and are usually considered a good soundproofing material, if the wall is not constructed well, noise can travel through it.

Sockets placed back to back create a weak zone where air can pass through and there is less resistance to sound. It is always best to stagger the layout of electric fixings, where possible. Likewise, other holes or cracks in brickwork will decrease the soundproofing qualities as there is less resistance and sound can seep through like water. To improve this, use an appropriate wall filler on holes and cracks.

Cavities in walls can also mean reduced soundproofing. A sound that enters an open space will bounce around and can turn your wall into a speaker. This is why we fill all cavities with acoustic mineral wool which can absorb sound.

Is brick good for soundproofing?

Yes, brick is good for soundproofing compared to other wall materials like studs and plasterboard. Bricks have a high mass which is good for reflecting noise and insulating your space. While bricks are good soundproofing materials, the wall needs to be thoughtfully constructed for the best soundproofing results.

Just having a brick wall does not mean you won’t need any soundproofing. Many brick walls need additional layers of mass and insulation to block out noisy neighbors. Wall-mounted TVs are a big problem in this area as the source is directly next to the brickwork. Brick wall soundproofing will further increase the mass of your wall and good systems also add in decoupling devices.

Does brick absorb sound?

Brick does not absorb sound, instead brick reflects sound which is a soundproofing quality. Sound absorption is used to reduce reverberation (echo) and is achieved with soft materials. Reflection of sound is done with high-mass materials (like brick) and this will soundproof a space. This means that a bare brick room will echo without additional soft materials, like furniture because the sound will be reflected from wall to wall.

Most people use acoustic panels to absorb sound. You may have seen these in music studios but people use them in homes, offices and cafes to make sound clearer.

Is brick a good sound insulator?

Yes! Brick is a great sound insulator as the high mass reflects noise away. This means brick is a good soundproofing material and brick walls are able to reflect more noise than stud walls. Some brick walls will still need soundproofing to reduce flanking transmission or combat weak areas. Also, not every brick is made equal, some will have a higher mass, and others a more open structure. Bricks which are more porous will not be as effective at soundproofing, because air is able to enter the brick.

Does a brick wall reduce noise?

Yes, a brick wall will reduce noise, more than a stud wall. Brick walls have a high mass which is good for soundproofing against airborne noises like TV, music, and talking. Some brick walls will have a higher mass, because the bricks are different, and these will be more effective.

Some brick walls will suffer from flanking transmission which is when sound travels around the main partition by using electric sockets, wall fixings, and cracks. If these weak areas are reinforced, the overall soundproofing will improve.

Why is sound transmitted easily through plaster walls but not through brick walls?

Sound is transmitted easily through plaster walls but not through brick walls because bricks have a higher mass. High mass reflects noise, which is how soundproofing works. While stud walls can be improved, they naturally have a low mass and cavity space. Cavities are a big weakness and should be filled with acoustic mineral wool which prevents amplification through reverberation. Brick walls are naturally better at blocking noise, but not perfect, and many benefit from soundproofing.

What is a decoupling brick wall?

A decoupling brick wall uses sound isolation materials to create a physical separation between two materials. This is done for the highest soundproofing results as it is the most effective way to block sound for the space used. An isolation clip is the best way to make a decoupled brick wall. The clip screws into the brickwork and holds a metal channel away from the wall. This channel takes the load of the soundproofing panels and thus a new partition is decoupled. The cavity created is filled with acoustic mineral wool.