How to soundproof a brick wall
Hearing noise through a brick wall can be surprising, given their solid and dense structure. However, brick walls aren't entirely soundproof. In this post, we'll explore the key reasons sound can pass through brick walls and share the most effective methods to enhance a brick walls ability to block and minimise noise transfer.
Why can I hear my noisy neighbours through my brick wall?
Hearing neighbours in a semi-detached or terrace house is a common issue, as the shared wall between the two homes can easily transmit sound. This wall, known as a party wall, often lacks sufficient soundproofing to block noise effectively. Here are some common reasons why sound might be travelling through your brick party wall:
1. Density and condition of the bricks:
- In many terraced and semi-detached houses, the party wall was built with minimal soundproofing in mind, particularly in older homes. Some brick walls will have weak areas, as not every brick is made with the exact same density and more porous bricks are less dense and less effective at blocking sound.
2. Wall cavities:
- Sound can enter a cavity, bounce around and amplify (similar to a drum) hence the term 'the drum effect'. This can occur when a fireplace is removed on one side (or both sides) of the brick wall.
3. Airborne Sound Transmission:
- Airborne sounds like voices, TV, and music travel through the air, hitting the brick party wall and causing it to vibrate. Without a dense or insulated barrier, these vibrations pass through to your side of the wall. This is particularly common if the wall has empty cavities or lacks mass. Hearing noise from a TV through a neighbours wall is also increasingly more common since the mounting of large TV's (directly onto dividing brick walls) has became more and more common.
4. Brick Walls Reflect Sound but Don’t Absorb It:
- Brick walls are dense, which helps block some sound. However, they don’t absorb sound waves well, meaning sound can sometimes pass through if it’s loud or low-frequency. For instance, lower bass sounds can vibrate through brick more easily than high-pitched sounds. Low-frequency noises like snoring, bass music or low voices, can vibrate through solid walls. Bricks are rigid, which means when low-frequency sounds hit the wall, the vibrations can pass through to the other side.
5. Structure-Borne Noise:
- Structure-borne sounds such as footfall, closing doors, and appliances like washing machines cause vibrations to travel through the wall structure itself. Structure-borne noise happens because the impact causes the building elements to vibrate. These sounds are harder to block because they move through the building structure rather than simply through the air.
6. Flanking Noise:
- Occasionally, noise doesn’t go directly through the shared brick wall but instead "flanks" around it. This can happen through connected walls, floors and ceilings. Therefore, occasionally, the sound you’re hearing may be travelling through these connected elements, rather than directly through the brick wall itself. To check this, do a simple ear test when you can hear the noise and listen to where it is loudest.
7. Gaps, Cracks, or Poorly Sealed Outlets:
- Gaps or cracks in the wall and old mortar, poorly sealed electrical outlets, or plumbing fixtures can allow sound to travel through the wall more easily. Sound can travel through the smallest of openings. Think of it like water. If water can find a path, so can sound.
How to reduce noise from noisy neighbours through a solid brick wall
To soundproof a brick wall separating neighbours, it's essential to use tried and tested soundproofing methods.
1. Decouple the wall using the
ReductoClip System. Physically build an internal stud frame a minimum of 10mm away from the existing brick wall to give the highest level of soundproofing. Sound passes through solid materials and by creating a physical airgap, it makes it much harder for sound to pass through your neighbours brick wall into your room.
2. Add mass to the brick wall. Heavy dense materials are extremely effective at blocking airborne noise. Materials like
Mass Loaded Vinyl,
FlexiSound and
Acoustic Plasterboard.
3. Fill any empty cavities with
Acoustic Mineral Wool. This will stop sound from bouncing round empty cavities, creating a chamber of sound which amplifies the sound making it louder.
4. Install soundproofing panels such as
SoundBoard 4. A direct to wall soundproofing panel which features a 3mm layer of mass loaded vinyl. A 9mm layer of closed cell foam sandwiched between a further 3mm layer of mass loaded vinyl and a layer of 15mm acoustic plasterboard. Ideal for low mass structures like internal stud walls, but can be used on brick walls when there are space constraints due to window or door frames.
Direct to wall soundproof panels on brick walls do not perform as well as the
ReductoClip Independent or
ReductoClip Direct to Wall system as the soundproofing is not de-coupled from the brick wall.
Soundproofing a brick wall using the ReductoClip System
The
ReductoClip system is a highly effective soundproofing solution specifically designed to combat unwanted noise issues from noisy neighbours travelling through brick walls. An innovative sound isolation clip and bar solution creating a
"decoupling"
layer, prevents sound vibrations from easily passing through brick wall structures. Extremely high performing and the slimmest clip and bar system on the market, achieving excellent sound reduction and minimal space loss.
Here’s a guide to soundproofing with the
ReductoClip system:
How the ReductoClip System Effectively Soundproofs a Brick wall
The
ReductoClip Independent System works by creating a floating wall (or ceiling) separated from the main wall structure by isolation clips and acoustic furring channels. This separation helps block airborne noise across all frequencies, including lower bass tones from music or male voices.
Installation Steps for Soundproofing a brick wall with the ReductoClip System
ReductoClips are attached to an independent stud frame built a minimum of 10mm away from the offending brick wall. High mass layers and sound dampening materials are attached to the Reducto Furring Bars which are slotted in-between the ReductoClips.
The ReductoClip Independent Wall System effectively blocks noisy neighbour sounds through a brick wall. With a total build-up of just 120mm, it stands as the slimmest independent soundproofing system on the market.
Soundproofing a solid brick wall with the ReductoClip Independent System
Alternatively, ReductoClips can be attached directly to the brick party wall. This will give an excellent sound reduction and is a slim 60mm (again the slimmest direct to brick wall clip and bar system on the market). Not as high performing as the ReductoClip Independent System which fully decouples the soundproofing layers from the brick wall, it is still an outstanding system for performance v's space loss.
Soundproofing a solid brick wall with the ReductoClip Direct to Wall System
- Acoustic mineral wool is slotted between the stud frame (ReductoClip Independent System) or attached directly to the brick wall between the clips and bars using contact adhesive spray (ReductoClip Direct to Wall System).
- Acoustic channels
(also known as furring channels or bars) are 'snapped' into the ReductoClips. Soundproofing layers are then installed onto the Reducto furring channels. By using The ReductoClips and bars, soundproofing materials remain decoupled from the main brick wall structure. This separation is essential for absorbing sound energy from a noisy neighbour before it passes into your room.
- A first layer of Acoustic Plasterboard is fixed to the ReductoClip Furring Channels. Leaving a 5mm gap around the perimeter edge of the wall, floor and ceiling.
- FlexiSound 5 is then attached to the Acoustic Plasterboard. FlexiSound is self-adhesive and requires no fixings. Is ultra thin (5mm) and adds a huge amount of mass to the brick wall. Used as part of the ReductoClip buildup, it also helps to dampen sound energy and vibration.
- A second layer of Acoustic Plasterboard is then installed, sandwiching the FlexiSound between the two layers.
- Acoustic sealant is then applied around the perimeter of the soundproofing layers. A high strength, flexible sealant specifically formulated to seal perimeters and gaps where sound may escape.
Conclusion: Soundproofing a brick wall
To effectively soundproof a brick wall, it's essential to reduce sound transmission by decoupling surfaces and enhancing the walls ability to absorb and dampen sound energy. Sound travels through solid materials via direct contact. Therefore, create a separation, such as building a new stud wall with a 10mm gap, making it harder for vibrations and sound transfer to travel.
Adding resilience to a brick wall with ReductoClips, allows the wall to absorb vibrations, much like how a car's suspension smooths out road bumps.
Additionally, adding layers of dense materials like
FlexiSound and
Acoustic Plasterboard blocks airborne noise. These two types of materials are used as both are effective at reducing different sound frequencies.
For superior noise reduction through a solid brick party wall, the
ReductoClip Independent Wall System offers an all-encompassing solution that meets all soundproofing needs.
