Best Soundproof Flooring Underlays

Best soundproof flooring underlays everything you need to know

The single most common soundproofing solution for floors is soundproof flooring underlays. Whether you are looking to stop the sound of a small child running across the floor or meet Part E regulations, soundproofing underlays play a big part in sound insulating floors.

We are often asked if soundproof underlays will soundproof floors against airborne and impact sounds, and the answer is yes. The best soundproofing underlay mats incorporate mass for airborne soundproofing and closed-cell foam for reducing impact sounds.

What’s the difference between airborne and impact noise

Before we get into the underlays, we thought it would help explain what we mean by airborne and impact noise.

Airborne noise: Sound that transmits through the air is classed as airborne noise. Common types of airborne noise include conversation, TVs and music.

Impact noise: Caused when an object strikes the floor, and vibrations transmit into the room below. Common types of impact noise are footfall, movement over the floor, and dropping an object.

What is the best way to soundproof a floor?

The best way to insulate floors for sound is to follow these soundproofing principles.

• Add mass to the floor to block airborne sound. Materials with high mass reduce airborne sounds like TV noise and talking.
• Improve the floor’s ability to absorb sound. Sound absorption is key to reducing impact noises such as footfall.
• Soundproofing floors with timber joists will benefit from additional acoustic insulation inside the floor cavity, which adds more mass and improves the sound absorbing performance of the floor.
• As with most soundproofing solutions, floors benefit from a combination of materials offering the best sound insulation level rather than a stand-alone solution.

If you are considering insulating floor joists against sound, we have a range of acoustic insulation for soundproofing floors. As a rule, we recommend using 100mm thick slabs, as this fills a good portion of the cavity. The other factor to consider is the density of the insulation; we recommend using 60kg/m3 slabs, as these offer the best level of soundproofing without paying more for diminishing returns acoustically. You will pay more for higher density slabs and not see the return on your soundproofing.

Best soundproof flooring underlays

There are various soundproof underlays available. Here are some of the best soundproofing underlay options.

How acoustic underlays soundproof floors

We have already shown the two types of sound acoustic underlays will stop. Here, we will look at the most suitable underlays for soundproofing your floor and work with your required finish.

How does an underlay block airborne sounds?

The material that soundproof underlays use to add mass is mass-loaded vinyl sheets.

Mass-loaded vinyl is a high-density soundproof membrane used to reduce airborne sound in acoustic underlays and as a stand-alone floor soundproofing product.

Barrier Shield mass-loaded vinyl sheet 10kg/m2

How do acoustic underlays block impact sound?

Acoustic underlays that block impact sounds have a layer of acoustic-grade closed-cell foam. These foams absorb impact sounds created by footfall and movement across the floor.

1. Mass-loaded vinyl to reduce airborne noise
2. Acoustic closed-cell foam to absorb impact noise
3. Mass-loaded vinyl to reduce airborne noise

The best soundproofing underlay

The best soundproof underlay has to offer the most overall soundproof insulation, and that’s the Noisestop F7 Plus. Reducing both impact and airborne noise due to its tripled layered configuration of two layers of the mass-loaded vinyl sandwiching the closed cell acoustic foam.

Noisestop F7 Plus

The acoustic closed-cell foam and the two layers of mass-loaded vinyl incorporated within the Noisestop F7 Plus work perfectly together to improve the sound insulation of any floor.

• Reduce airborne and impact noise
• Triple-layered for added protection against airborne sound
• Quick and easy DIY install
• Suitable for use over concrete and wooden floors
• Ideal for carpeted floors and most domestic floor finishes

Some floor finishes would require our 9mm interlocking MDF overlay board.

Offering the best overall sound insulation means using this underlay without needing acoustic insulation. However, incorporating sound insulation inside wooden floors will significantly reduce sound transmission between them.

Best acoustic underlay to reduce impact noise

The best acoustic underlay for reducing impact sound is the 12mm Noisestop Acoustic Underlay. We have chosen this underlay as the best for impact sound as it has performance levels similar to those of the thicker 15mm underlay. The single layer of vinyl and the closed-cell foam offer a good balance of sound insulation.

Noisestop Acoustic Underlay

The acoustic closed-cell foam and the layer of mass-loaded vinyl incorporated within the Noisestop Acoustic Underlay work perfectly together to improve the impact sound insulation of any floor.

• Reduces impact noise
• Double-layered to reduce impact sound
• Quick and easy DIY install
• Suitable for use over concrete and wooden floors
• Ideal for carpeted floors and most domestic floor finishes

Some floor finishes would require our 9mm interlocking MDF overlay board.

Combining the Noisestop Acoustic Underlay with acoustic insulation between floor joists will significantly improve the sound insulation of wooden flooring.

Best soundproofing underlay for reducing airborne noise

Our choice of the best material to soundproof a floor against airborne noise is one of our thinner solutions. The Noisestop Barrier Shield 10kg/m2 mats are our pick for soundproofing floors against airborne noise.

10kg Barrier Shield

We chose Barrier Shield because it is the same material used in all the other acoustic underlays. A Barrier Shield is a sheet of mass-loaded vinyl. As we have already mentioned, the vinyl part of an acoustic underlay stops the airborne sound.

• Reduce airborne noise
• DIY friendly installation
• Cost-effective

This must be considered if you are looking for an option to insulate your floor against airborne noise. The Barrier Shield will not reduce impact sound transfer on its own; however, combined with our impact mat, you will soundproof your floor against impact and airborne noise.

Best soundproof underlay for floors with carpets

Either of our two main soundproof underlays is significant below carpets; Noisestop F7 Plus and Noisestop Acoustic Underlay can be fitted below carpets without the need for traditional carpet underlay.

An acoustic underlay will give the same feeling underfoot as a normal underlay while absorbing impacts through the floor. Standard carpet underlays are produced using a much lower-grade open-cell foam, which doesn’t have the strength and stability of a closed-cell foam, which is why carpet underlays don’t stop the impact noise.

Best soundproofing option for laminate and engineered floors

All the acoustic underlays we provide work well below laminate and engineered floors. We have chosen the Noisestop Impact mat because it is the most suitable for this floor type. This floor type generates higher levels of impact sound than carpet; therefore, we feel the impact mat is best due to the installation method compared to thicker acoustic underlays.

Noisestop Impact Mat

• Reduce impact noise
• Slim profile
• Easy to install
• Cost-effective

The drawback with thicker underlays is you would require an additional layer over the soundproofing to stabilise the laminate. The best thing about the Impact Mat is that you can install your chosen floor straight over the top.

How to soundproof floors

Soundproofing floors requires adding mass, sound absorption, and decoupling. It follows the same principles as soundproofing walls and ceilings. By improving the floor’s ability to absorb sound, you will successfully soundproof the floor against airborne and impact noise.

• To block airborne sound, add mass to the floor area. Acoustic insulation slabs and underlays are materials used to add mass to the floor. Soundproof between floor joists to block and absorb noise, acoustic underlays with mass-loaded vinyl add to the floor’s mass.
• Improve the floor’s ability to absorb sound by using acoustic underlays to absorb impact noise and acoustic insulation inside empty floor cavities to stop sounds from resonating inside the floor joist.
• Use acoustic underlay mats to decouple floors to isolate the structure from the floor finish. Soundproof mats and membranes over the subfloor isolate the floor finish and stop sound from transmitting into the floor and the rooms below.

How to install acoustic underlays

• Ensure the floor on which you are laying the mats is free of dirt and debris and that any holes have been filled.
• If you use gripper rods or perimeter edge strips, they should be installed before the acoustic underlay.
• Lay the soundproof mats over the floor in a brick-bond pattern if possible.
• The mats should be fitted tightly together with no gaps between them.
• Use the High Tack Tape to secure the joins.
• Lay your floor finish or carpet underlay over the soundproof matting.

Fitting hard floor finishes over acoustic underlay mats

If you plan on using laminate, engineered or LVT over acoustic underlays, use a resilient layer below the floor finish.

Using an interlocking floor ensures a stable base for your chosen flooring. It is important to note that the floor will be more secure if it interlocks. You will risk movement if you use flooring that doesn’t lock together. Our 9mm T&G interlocking MDF sheets are ideal for laying over acoustic underlays to secure the final floor finish.

Soundproofing products to install acoustic underlays

To fit your soundproof underlays, you might need some of these products.

If you use a carpet underlay with your soundproofing underlay, you will need to raise the height of the carpet gripper rods. Perimeter edge strips fitted below the gripper rods will ensure the gripper rod is at the required height for your carpet.

Secure the underlay mats with the High Tack Tape along the edges of the mates as they butt together.

Our 9mm interlocking MDF sheets over the acoustic underlay reduce any potential movement in laminate flooring and LVT.

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