What is the best soundproof acoustic insulation?

Lets dispel the myths between acoustic insulation and soundproofing. Often, we think of insulation as having thermal connotations -keeping buildings warm in winter and cool in summer. Acoustic insulation and soundproofing are pretty much interchangeable terms and when people are using these terms, it's usually to look at ways in which to block the passage of sound.

However, acoustic insulation (acoustic mineral wool) is only designed to absorb sound in cavities, and is not a full soundproofing system in its own right.

What is soundproofing?

Soundproofing is the process of blocking the transmission of sound between different spaces. For example, blocking sound through a party wall from noisy neighbours. Or blocking unwanted sound and noise from above or below in rooms within flats and shared buildings.

When we talk about soundproofing we are talking about reducing unwanted noise from the source. Often in domestic situations this comes from noisy neighbours and the transference of that sound energy to the recipient (you). For more of an in depth read take a look at how to soundproof a wall against noisy neighbours.

Soundproof Insulation Materials Explained

Soundproof insulation, also known as acoustic insulation or soundproof acoustic insulation, refers to the materials and techniques used to reduce or block the transmission of sound between different spaces. The primary goal of soundproof insulation is to create a more comfortable and quiet environment by preventing the passage of sound waves.

There are various types of soundproof insulation, and they can be applied to walls, ceilings, floors to minimise the impact of noise. Here is a list of some common materials which are often classed as soundproof insulation materials, however lets separate the fact from the fiction:

Fiberglass Insulation:

Fiberglass is not dense enough to provide effective sound insulation, a more effective option would be to use Acoustic Mineral Wool.

Foam Panels:

Egg box type foam panels are not to be used as soundproof insulation. They are sometimes used in the likes of music studios to help reduce echo and reverb.  A higher performing alternative would be ProSound Acoustic Wall Panels, which are specially designed for sound absorption, (also not suitable for soundproofing). Acoustic Wall Panels are extremely effective at reducing echo and reverberation (often in communal spaces such as village halls, schools, offices and music studios and restaurants).

Acoustic Mineral Wool Insulation:

Acoustic mineral wool is a dense material that effectively absorbs sound. It is commonly used in wall and ceiling cavities. It is not soundproofing on its own, but is used alongside tried and tested wall and ceiling systems such as the ReductoClip Wall and ReductoClip Ceiling Systems.

Mass-Loaded Vinyl (MLV):

MLV is a dense, thin rubber-like material that adds mass to surfaces, reducing sound transmission. Again, used as part of a soundproofing solution such as the SoundBoard 4 Direct to Wall Acoustic Panel.

Green Glue:

Green Glue is a dampening compound applied between layers of plasterboard (or drywall) to help dampen vibrations. A more effective alternative to Green Glue would be to use FlexiSound 5.

Cork Insulation:

Cork is sometimes marketed as having sound-absorbing properties when looking to reduce impact noise. The recommendation would be to use a tried and tested floor soundproofing solution such as SoundMat 3 Plus, which is effective at blocking both airborne and impact vibrations as it adds far more mass to the floor which is essential for blocking airborne noise whilst also featuring a layer of closed cell foam to help dampen vibrations and sound energy from the likes of footsteps.

Learn more about Green Glue and soundproofing

What is the best way to soundproof a room?

Phil Lyons is head of soundproofing at the UK's largest supplier of soundproofing materials The Soundproofing Store. He explains how for successful soundproofing there are some essential key principles which need to be followed.

Phil goes on to explain the 3 main principles of soundproofing: Adding mass, isolating (or decoupling) and damping.

1. Decoupling:

• Decoupling and isolation involves breaking the direct connection between surfaces to reduce sound transmission. Phil explains how sound waves travel easily through connected surfaces, so breaking this connection is important for effective soundproofing.

2. Adding Mass:

• Increasing the mass of walls, floors, or ceilings can help block airborne sound transmission. Phil explains how this can be achieved by using dense materials like Acoustic Plasterboard, FlexiSound and direct to wall acoustic panels like SoundBoard 4 which features two layers of Mass-Loaded Vinyl (MLV).

3. Damping:

• Damping involves reducing vibrations in walls, floors and ceilings by using materials that help to absorb sound energy and vibrations. Phil uses the analogy of how the suspension in your car works when it absorbs bumps the road. He goes on to explain that in walls and ceilings, "ReductoClips do this by acting like a shock absorbing suspension system to dampen high levels of sound energy and vibration."
  

Is Acoustic Insulation the same as Soundproofing?

Soundproofing solutions can include the use of acoustic insulation materials to help block noise within peoples homes, places of work and studios. Acoustic mineral wool is one of those products and is designed to absorb airborne sounds in the cavities of timber and metal party walls, timber joists and any sealed chambers where sound can reverberate. Using an acoustic insulator can effectively absorb sound and when used with other soundproofing solutions, can help to bring floors and walls into compliance in meeting (and when used as part of a build-up) exceed Part E Building Regulations.

Featured below is the ReductoClip System which includes the use of acoustic mineral wool (soundproof insulation) as part of the complete soundproofing system. It is important to note that acoustic insulators are not a loft type insulation wool with high thermal qualities. This is because they are produced to a specific density to give maximum sound absorption. Acoustic mineral wool delivers a high level of sound absorption and acoustic insulation within cavity partitions. 

Top tip - there are many branded products out there which claim to offer effective acoustic insulation. Always check the mass of the product. This is key as to how well it will perform in blocking sound when soundproofing your wall, floor or ceiling. This is discussed in more detail below.

Acoustic Mineral Wool and Soundproofing

Why is acoustic insulation not a solution for soundproofing on its own?

Acoustic insulation (or soundproofing) is all about adding mass, mass and more mass. This helps to stop airborne noise from passing so easily through a structure. The most effective soundproofing solutions don't just add more of the same mass, they add mass which is comprised of different materials. This is very important, as different materials are better than others at blocking different types of sound. 

The other principle in effective soundproofing is to decouple or dampen the building. Sound travels as a vibration when it hits a wall or floor. To prevent sound vibrations travelling through buildings, the vibration needs to be dampened to stop it from travelling through. The most effective way to stop sound vibration energy from travelling through is to decouple the structure and then add mass.

What is the highest performing acoustic insulation system?

The ReductoClip System for walls decouples the original structure by creating a room within a room. This achieves the highest level of acoustic insulation and soundproofing. Not only does the ReductoClip System create an exceptional soundproofing performance within domestic homes against noisy neighbours, but it is also used as a professional system in soundproofing recording studios and music rooms. The ReductoClip System is also the go to system for Trade and Building specifiers when needing to exceed Part E building regulations.

How does the ReductoClip™ System for walls work? 

How to soundproof a wall using the ReductoClip™ Independent System

The  ReductoClip System  for walls, works against both airborne noise (talking, TV noise etc) and Impact noise (moving furniture, footsteps etc). One of the elements to the system is the use of acoustic mineral wool (as mentioned above) which acts as an acoustic insulator. The acoustic mineral wool is added between the timber battens to absorb airborne sound in the cavities of timber and metal party walls. The acoustic mineral wool provides acoustic insulation by significantly improving acoustic performance and reducing reverberation. 

Acoustic insulation boards for walls

The best performing direct to wall acoustic insulation board is the ProSound™ SoundBoard4™If you don't have the space to lose (building a room within a room) with the ReductoClip System, then this space saving option offers a good performance against noisy neighbours. The SoundBoard 4 acoustic board is only 30mm thick and can easily be installed by a competent DIYer or tradesperson. 

As previously mentioned, the best performing acoustic insulation needs to be heavy (mass blocks sound). Unlike other acoustic insulation solutions, the SoundBoard 4 features 4 layers of different high mass soundproofing materials, (which block a wide range of sound frequencies) all laminated together in one board. The SoundBoard 4 adds 34.83kg of mass to your wall and a dampening layer to prevent the sound energy (vibration) from travelling through.

SoundBoard 4™ Components:

• 15mm Acoustic Plasterboard finish (ready for a plaster skim finish, or heavy duty backing paper finish) 
• 3mm Mass Loaded Vinyl (doesn't absorb sound and designed to replace lead in soundproofing)
• 9mm Closed Cell Foam (dampens sound energy and vibrations)
• 3mm Mass Loaded Vinyl (a further layer of Mass Loaded Vinyl)

Does thermal insulation reduce noise?

The short answer is no. We often get asked if products used for thermal insulation (the likes of Kingspan or Celotex) will also be effective at soundproofing. To a certain extent by having the thermal material added it arguably offers more mass than it did before, but this would be so negligible that it wouldn't mean walls, floors, or ceilings had any further soundproofing capabilities than they did previously. 

Acoustic insulation for ceilings

In this article we have so far focused on acoustic insulation for walls. If you are looking at acoustic insulation for your ceiling , then similar to walls, you also need to:

• Improve the mass of the ceiling, by adding high density materials.
• Improve the ability of the ceiling to absorb sound energy and vibrations. (Without this part, the adding of any mass will have very little effect on impact noise).
• Use different materials of high mass (as we discussed above for walls).

A useful exercise is to do a 4 point acoustic insulation check:

1. Is the ceiling a timber joist ceiling, or a concrete ceiling?

2. Where is the noise coming from? 

3. What type of noise is it? Airborne, Impact, or both?

4. How loud is the noise?

Further information on acoustic insulation for ceilings, is highlighted within our blog  How to Soundproof a Ceiling .

ReductoClip System for ceilings

How to install the ReductoClip Timber Ceiling Solution

What is acoustic flooring?

By limiting the transference of sound travelling through concrete or wooden floors, you can create peace and quiet in your own home by laying acoustic matting.

Again, it's useful to do the 4 point acoustic insulation check:

1. What is the floor made of? Timber joist, or solid concrete?

2. Where is the noise coming from? The room below, or above?

3. Is the noise vibration impact, or airborne?

4. How loud is the noise on your side of the floor?

Can you insulate between two floors to reduce noise?

Yes, absolutely and the process couldn't be easier when using an acoustic underlay such as the ProSound™ Reverso SoundMat or the ProSound™ SoundMat™ 3 Plus. Both of these acoustic mats help to block noise from above, or below. 

To successfully insulate a floor against sound you need to:

• Improve the mass of the floor, by adding high mass density products (a running theme for walls, ceilings, and floors!)
• Improve the ability of the floor to absorb sound energy and vibrations (footsteps). As mentioned previously, without this, the addition of any mass will have very little effect on impact noise.
• Use acoustic insulation between the timber joists to eliminate any sound resonating and amplifying within this sealed chamber.
• Use different materials of high mass, as simply using more of the same material will never have the same result as using different materials. (For all of the reasons we have mentioned above).

What is the best acoustic matting?

ProSound™ Reverso SoundMat™ is the only high performing soundproofing mat designed for both hard and soft floor finishes. When used hard side up, (unlike with other acoustic underlays) there is no need for an over boarding layer before installing most final floor finishes. The Reverso SoundMat is ideal for blocking loud levels of airborne and high impact noises and is suitable for all final floor finishes. 

Reverso SoundMat Components:

• 6mm Fibre Cement Board (provides a stable base for hard final floor finishes and adds mass to block airborne noise)
• 9mm Closed Cell Acoustic Foam (for impact noise such as footsteps and unlike open cell, or recycled chip foam will not absorb water should there be any water damage in the future)
• 3mm Mass Loaded Vinyl (further airborne noise blocking capabilities and acts as a luxury carpet underlay)

The Reverso SoundMat is a simple DIY install, without the need of adhesive and can be used under underfloor heating (hard side up).

ProSound™ SoundMat™ 3 Plus  features an innovative 3 layer design which is effective in helping to tackle the unwanted noise of everyday living. This particular acoustic mat delivers an outstanding performance against loud levels of noise, such as clear conversation, TV noise and heavy footsteps. At only 15mm thick, this acoustic matting saves you space compared to other traditional acoustic underlays.

SoundMat™ 3 Plus Components:

• 3mm Mass Loaded Vinyl (designed to replace lead in soundproofing)
• 9mm Closed Cell Foam (for impact noise, such as footsteps)
• 3mm Mass Loaded Vinyl (further airborne noise blocking capabilities)

These acoustic sound mats are simple to install by a competent DIY'er or tradesperson and are applied directly to the floor, without the need for any adhesive. The video below shows the easy installation of the acoustic mats.

Installing SoundMat 3 Plus acoustic underlay matting

Installing Reverso SoundMat acoustic underlay

Summary of the best soundproof acoustic insulation

Acoustic insulation can be applied to walls, floors and ceilings to soundproof against unwanted noise. By following the 4 step acoustic checker, this can help you to help make the correct product choice. Top performing solutions like the ReductoClip System and SoundMats have also been highlighted, due to their superior performance in soundproofing, along with their ease of installation (all of which can be fitted by a competent DIY'er or tradesperson).

Author

Phil Lyons heads up the technical team within The Soundproofing Store, bringing with him a wealth of expertise in the field of soundproofing and acoustics. With considerable experience in addressing a variety of noise-related challenges, Phil plays a crucial role in assisting customers in finding effective solutions to all types of unwanted noise problems.

Phil also serves as the head of the studio department, specialising in soundproofing music rooms and band practice spaces. His proficiency extends to regularly collaborating with builders and specifiers on projects that require compliance with Part E Building Regulations. Phil regularly demonstrates his versatility and extensive knowledge of soundproofing across all situations.

An authoritative voice within Soundproofing, Phil also fronts The Soundproofing Store YouTube channel, sharing his extensive knowledge and expertise with people all over the world.