How to soundproof a wall?

How to soundproof a wall: Case study

How to successfully soundproof a wall?

To successfully soundproof a wall there are three main principles which need to be applied:



1. Improve the mass of the wall, by adding heavy, high density products to help block airborne sound
2. Use different products of high density and high mass. Simply using more of the same, or doubling up of the same materials won't be as effective as using a combination of high mass materials. This is because different materials perform better at blocking different sound frequencies
3. Decouple the original wall to help the wall to absorb sound energy and vibrations. This third point is important, as without it, the addition of products of different mass (points 1 and 2) will have very little effect.

The Noise Issue

Our customer was experiencing unwanted airborne and impact noise from their next-door neighbours, which included:

• Footsteps running up and down the stairs
• Light switches being turned on and off
• TV noise
• Talking

Although they get on extremely well with their neighbours, they were mindful that they owned their property and the adjoining property was a renal. The neighbours had lived there for many years and were thinking of moving. Our customer contacted us, as they were concerned that if they had new neighbours (who weren't so respectful of the noise between the two properties), it could make for strained relationships and unwanted noise could become more of an issue. They wanted to look at soundproofing against the noise they were experiencing from their neighbours and friends next door and to also to future proof their home against any potential unwanted noise in the future, with new neighbours.

What is the right wall soundproofing solution?

Everyone's noisy neighbour issue is unique and the correct and most effective wall soundproofing solution depends on the following factors:

1. The structure of the wall. Is the wall a stud or solid wall? (In this instance it was a solid brick party wall)
2. How loud is the noise being heard? Can you hear every word, make out the TV programme your neighbour is watching, or is it muffled noise?
3. What type of noise do you need to soundproof the wall against? Is it TV noise, talking, shouting, loud music (airborne noise) or is it footsteps, vibrations from doors banging, (impact noise). In this instance it is a combination of both
4. Is there a chimney on the wall? If there is a chimney, do a simple ear test when you can hear the unwanted noise and listen to hear if the noise is coming through the alcoves, and/or also coming through the chimney breast. In this instance the majority of sound was coming through the alcoves and the customer didn't want to soundproof behind their log burner. They were made aware that by not addressing the chimney, there was the potential for some of the noise they could hear to still be heard through the fireplace. However, as this was minimal, they were more than happy to address the main problem, which was that of the alcoves.

Learn more about why a chimney naturally blocks more sound and why 9 times out of 10 it doesn't need soundproofing: How to Soundproof a Chimney 

What is the best performing wall soundproofing solution?

The Soundproofing Store's highest performing wall soundproofing solution is the ReductoClip Independent Wall System. This sound insulation solution for walls is the highest performing against all unwanted noise problems through a party wall, including excessive airborne and impact noises. It ticks all of the boxes mentioned in the three main principles above and creates a room within a room, isolating and decoupling the original wall, delivering the highest possible level of soundproofing.

The ReductoClip Independent Wall System is the chosen system in this scenario as it provides the highest performance against the airborne and impact noise currently being heard by our customer and would also provide the maximum benefit for any potential excessive airborne or impact noise in the future from potential new noisy neighbours. The ReductoClip Independent System is 120mm thick from the original walls and due to our customer having deep alcoves within their lounge wall, this wasn't an issue.

The below image shows the thickness of the ReductoClip Independent System against the depth of the alcoves. There will still be a large depth of alcove even once the system has been installed.

Minimum loss of space (the depth of a soft drink can 120mm)

What are the benefits of the ReductoClip Independent Wall System?

The ReductoClip Independent Wall System is the slimmest independent clip solution on the market. It delivers the highest levels of soundproofing within the home and helps to reduce the emotional stress caused by noisy neighbours. This system is also the go to choice for professional soundproofing in music and recording studios.

• Delivers the highest level of soundproofing at only 120mm space loss
• Creates a room within a room decoupling from the original wall to ensure sound vibrations no longer travel through the wall
• Outstanding performance against all levels and types of noise - brings peace and quiet to the home
• The perfect solution against the levels and types of noise being experienced by our customer and in future-proofing against all potential unwanted noisy neighbour noise
• Suitable for use on solid or stud walls
• Dual rubber design of the ReductoClips enables different sound frequencies to be absorbed - achieving a higher sound insulation performance than other clips which feature just one layer of rubber
• Wider Reducto furring bars mean an easier installation, with more surface area for attaching acoustic plasterboard onto
• Indents within the furring bars have a central and middle groove, therefore finding the midpoint on the furing bars is far easier when butting together acoustic plasterboard
• Outperforms resilient bars by up to 7dB. (The ReductoClip Independent System is a much higher performing system)
• Exceeds Part E building Regulations (this wasn't a requirement in this particular case study)
• DIY install - can be installed by a competent DIYer, or tradesperson

Installing the ReductoClip Independent Wall Solution

Remove skirting and coving

Firstly, the skirting and coving is removed from the existing wall. There wasn't any carpet in this instance, however, if there was, this would also need to be peeled back and gripper rods also removed.

Build the stud frame

Leave at least a 10mm gap in front of the existing wall and build the stud frame (50mm timber is used in this instance). Fix the stud frame to the floor, walls and ceiling, making sure NOT to fix it to the existing party wall but to the floor, side walls and ceiling.

Build vertical studs at 600mm centres.

Isolate the perimeter of the stud frame with isolation strip, to help eliminate any flanking vibration from the surrounding walls, floor and ceiling.

For plug sockets, ideally use surface mounted sockets. as this enables the wall to retain more mass, without holes (such as a plug socket) being cut out of the soundproofing and creating a weakness in the system.

At this stage in the installation, simply cut a hole and pull the cables through, ready to be surface mounted once the soundproofing has been installed.

Install Acoustic Mineral Wool

Install acoustic mineral wool between the battens. The slabs of mineral wool are slightly compressed either side of the frame and friction fit without the need of any fixings.

This high density acoustic mineral wool is added to what essentially would be a hollow chamber (once the plasterboard is added). Without the acoustic mineral wool, the sound could amplify within the chamber (this is also known as the drum effect). Leaving a hollow cavity behind the soundproofing can make the unwanted noise issue from next door even worse! The acoustic insulation of mineral wool helps to absorb this sound.

Installation of the ReductoClips and Reducto Furring Bars

ReductoClips are then attached to the stud frame:

• Maximum space between clips 1200mm (every two vertical battens on a 600mm centre frame)
• Maximum space between furring bars (vertical clip positions) 600mm
• Top row of clips should be a maximum of 150mm away from the ceiling (centre of furring bar)
• Bottom row of clips should be a maximum of 100mm from the floor (centre of furring bar)

Attach the furring bars to the ReductoClips making sure to overlap channels by 150mm and securing with 4 self tapping screws.

ReductoClip Positioning Diagram

The first layer of acoustic plasterboard

Then comes the installation of the first layer of acoustic plasterboard. Starting in the bottom of one corner. Use shims to keep the board 5mm off the ground and to leave a 5mm perimeter gap between all boards and the surrounding walls, ceiling and floor.

Dry wall screws are used to secure the plasterboard to the furring bars, whilst care is taken not to screw through to the timber and short circuit the furring bars.

Acoustic grade plasterboard is much heavier than standard plasterboard and it is this extra mass being added to the wall that helps to block airborne sound. The more dense the material, the harder it is for the sound to pass through the wall.

Tip! Before installing the plasterboard layers, the locations of the furring channels are marked on the surrounding walls in chalk or pencil. This helps to locate the position of the furring channels later on, once the first layer of plasterboard is added and channels are no longer visible.

The addition of Tecsound

Tecsound is then added to the wall. Designed as a replacement to lead, with a high mass of 10kg per meter squared, and coupled with unique visco-elastic properties, Tecsound provides an excellent sound insulation to block airborne noise. When Tecsound is added to the acoustic plasterboard, the visco-elastic properties also reduce the sound resonance and vibration of hard materials. Resulting in a higher performance. (Higher than mass loaded vinyl and green glue combined). 

Due to the mass of Tecsound, it is recommended to have two people to lift it. Although Tecsound is self adhesive and easy to use, a top tip would be to cut the Tecsound into smaller, more manageable pieces.

n.b. FlexiSound 5 is an excellent alternative to Tecsound. Offering the same high mass to thickness ratio and dampening properties, whilst also being more cost effective.

The second layer of acoustic plasterboard

The second layer of acoustic plasterboard is then added on top of the Tecsound, sandwiching the Tecsound between the two layers of acoustic plasterboard. With the second layer, start at the opposite side from where the first layer started, to stagger the joins. As with the first layer of acoustic plasterboard, a 5mm gap needs to be kept between the floor, ceiling and surrounding walls.

This is so that the wall still has the ability to move and flex and is therefore more effective at absorbing the vibration energy of the sound. The 5mm gap is then filled with acoustic sealant.

Sealing the perimeter with acoustic sealant

Remove any shims and fill the 5mm gap around the perimeter with a bead of acoustic sealant. Acoustic sealant can also be used and smoothed  across the acoustic plasterboard joins. Acoustic sealant is also used around the plug socket cables prior to attaching the surface mounted socket.

The final finish

Coving and skirting has been re fitted and the soundproof wall is now ready for a final finish, such as a plaster skim finish and painting. Once this has been completed, there is no way to know or tell visually that soundproofing has been installed.

How much did this soundproofing cost?

The cost for using the ReductoClip Independent system to soundproof both alcoves shown above, including VAT and delivery was less than £890.

Soundproofing performance

A before and after sound test was conducted on the wall, showing the walls performance before and after the ReductoClips and sound insulation was installed. The sound test in the neighbouring property was played at an average of 100dB (for both the before and after test). The average volume level in the receiving room (our customers lounge) was 53dB.Therefore showing that the existing brick wall was reducing 47dB for airborne sound prior to the soundproofing being installed.

The test taken after the ReductoClip Independent System was installed, showed the average volume level in the receiving room (the customers lounge) of 34dB. The soundproof wall is now reducing 66dB for airborne sound, meaning an exceptional improvement of 19dB.

In real terms this means a huge difference in the unwanted noise that was previously coming through from next door. If excessive noise is now made in the neighbouring property, e.g. running up and down the stairs, the TV is played loudly and shouting occurs, any noise heard in our customers lounge is extremely low and muffled, if heard at all.

The best way to soundproof a wall - summary

This article shows the best way to soundproof a wall, with a case study detailing the ReductoClip Independent Wall Soundproofing System. Highlighting a real life example for one of our customers and the best way to soundproof a wall. The Soundproofing Store's highest performing acoustic wall solution delivers an exceptional performance at blocking unwanted noise through a party wall. It is worth noting that the ReductoClip system can also be used to soundproof ceilings and the system is also the go to acoustic solution for soundproofing music studios and home cinema rooms.

There are also alternative wall soundproofing solutions to the ReductoClip Independent System, should the 120mm loss of space be too much to lose within the room. They won't be as high performing, but depending on the type and level of noise, still offer an excellent noise reduction v's space loss. 

One alternative is the ReductoClip Direct to Wall System, whereby the ReductoClips are added directly to the wall, rather than building a stud frame, which reduces the loss of space to only 60mm. There is also the SoundBoard 4, which is a direct to wall solution and achieves good results for standard household noise, (SoundBoard 4 isn't suitable for impact noise).

Should you require any help or advice on soundproofing walls, floors or ceilings, please don't hesitate to get in touch.