Noisy house? If it feels like you’re living with a herd of elephants and every little sound is amplified, acoustic underlay might be just what you need when choosing your next floor.
This guide covers everything you need to know about acoustic underlays, including the types of noise they combat, the different options on the market, and the best performers for carpet and laminate.
Ready for some peace and quiet?
In this guide
What is acoustic underlay?
Acoustic underlay is a layer of material you install beneath your flooring to reduce noise transmission throughout your house. It acts as a buffer, absorbing sound waves to stop them travelling through the floor and into other rooms.
Soundproofing underlays can make a huge difference in multi-story buildings, apartments and home offices where noise can be disruptive.
The difference between airborne and impact noise
Before we get into underlay specifics, it’s important to determine what kind of noise you’re dealing with in your property. The two main types are:
Airborne noise
Airborne noise is made by sound waves that travel through the air, such as people talking, dogs barking, music or TVs.
Impact noise
Also known as structure-borne noise, impact noise happens when an object collides with another, creating sound vibrations that travel through the building.
Common examples include footsteps, moving furniture around, dropping items or banging doors.
What type of noise does acoustic underlay tackle?
Acoustic underlay is most effective at absorbing impact noise, making it ideal for multi-level residential properties or settings where footfall is causing distraction or complaints.
If airborne noise is an issue for you, a high-mass underlay will dampen the noise by providing a cushioning layer between the subfloor and floor covering.
For complete airborne soundproofing, you’ll need to consider extra measures, like acoustic panels or tiles, wall and ceiling insulation and double-glazing.
The importance of impact sound reduction
When comparing acoustic underlays, the key figure to look at is the impact sound reduction, measured in decibels (dB). The higher the dB rating, the better the soundproofing performance.
For carpets, underlay with a rating over 40 dB is considered a top performer, and for wood or laminate flooring, a rating higher than 20 dB can significantly reduce impact noise.
The best types of underlay for combatting noise
There are several types of underlay on the market, including PU (polyurethane) foam, crumb rubber, sponge rubber, combination and felt. They come in a variety of densities, thicknesses and performance levels, so it’s important to do your research and get it right.
Here’s a breakdown of the two most popular acoustic underlays, how they work, and their features:
PU foam underlay
PU foam underlay is produced using polyurethane (‘PU’) foam, a versatile and resilient material known for its excellent cushioning properties. Here’s how it will help combat noise in your home:
- Impact noise: Its open-cell structure traps air and creates friction to absorb impact energy, converting sound into heat.
- Airborne noise: The same open-cell structure scatters and dissipates sound waves within the foam, reducing noise intensity.
- Key features: Lightweight for easy handling and installation, budget-friendly, provides cushioning and offers excellent thermal insulation.
- Good to know: It’s important to opt for thicker PU underlays to maximise noise reduction.
Sponge Rubber underlay
Sponge rubber underlay offers the best of both worlds: the durability and density of rubber with the comfort and easy to handle nature of sponge. Much like a bathroom sponge, this type of underlay features air holes, which is why it’s so good at reducing noise:
- Impact noise: Its high density and elasticity effectively absorbs and converts impact energy into heat, reducing noise.
- Airborne noise: Its dense, closed-cell structure blocks and scatters airborne sound waves, preventing transmission.
- Key features: Creates a firm but springy surface, provides insulation, is extremely durable and often includes a moisture barrier to protect against damp.
The best acoustic carpet underlays
When choosing soundproofing underlay for a carpeted area, it’s important to find the right balance of noise reduction, longevity and cushioning. If you choose a product that’s not thick enough, or too hard, you’ll end up sacrificing comfort underfoot.
In our experience, the thicker the acoustic carpet underlay, the better its performance.
Here’s our top picks:
1. SU LuxWalk 11mm Underlay
SU LuxWalk is a high-density PU foam carpet underlay that reduces impact noise by up to 45 dB. The supremely high 3.50 TOG value and 120 kg/m³ density rating are just a bonus.
You won’t find a better-value carpet underlay than this.
Key stats
- Material: High-density PU foam
- Thickness: 11mm
- Density: 120 kg/m³
- Impact noise reduction: 45 dB
- Tog: 3.50
Additional benefits
- Energy efficient ✔
- Enhanced comfort underfoot ✔
- Budget-friendly ✔
- Carpet lifetime guarantee ✔
- Perfect for living rooms and bedrooms ✔
2. Tredaire Colours Red 11.4mm Underlay
Tredaire Colours Red is a luxury sponge rubber carpet underlay that offers impact noise reduction of up to 46 dB as well as a high-density composition to help combat airborne noise.
At 11.4mm it feels wonderful underfoot, too, and can even be used in high-traffic areas.
Key stats
- Material: Sponge rubber
- Thickness: 11.4mm
- Density: 356 kg/m³
- Impact noise reduction: 46 dB
- Tog: 1.65
Additional benefits
- Luxurious comfort underfoot ✔
- Durable composition ✔
- Excellent carpet support ✔
- Carpet lifetime guarantee ✔
- Ideal for high-traffic areas ✔
3. Wilsons PlushWalk 12mm Underlay
Made using luxurious memory foam, Plushwalk offers market-leading impact noise reduction of up to 49 dB.
At a whopping 12mm thick, it also provides cloud-like comfort underfoot, giving any space the wow factor.
Key stats
- Material: Recycled memory foam
- Thickness: 12mm
- Density: 105 kg/m³
- Impact noise reduction: 49 dB
- Tog: 3.50
Additional benefits
- Premium quality ✔
- Unbeatable energy efficiency ✔
- A recovery rate of 92%, compared to 78% for PU foam ✔
- Carpet lifetime guarantee ✔
- Performs well in all areas ✔
The best acoustic laminate flooring underlays
Wood and laminate floors are stylish and practical, but can amplify noise (particularly footsteps) if not properly insulated.
Worth noting: Maintaining a wood or laminate floor’s integrity is crucial, so don’t scrimp on density when choosing your underlay.
Wood and laminate underlays are generally thinner than those suitable for carpets. This is to ensure a solid, stable base for the flooring. Therefore, they offer slightly less sound reduction.
Here’s our favourites:
1. Duralay Timbermate Excel 3.6mm Underlay
Timbermate Excel is a sponge rubber underlay for floating wood and laminate floors. It offers an impact noise reduction of up to 23 dB and an in-built vapour barrier to stop moisture ingress from the subfloor below.
A supremely high density of 706 kg/m³ also helps maintain the integrity of your laminate boards, providing a flat, stable base for installation.
A true all-rounder that’s a bestseller for a reason.
Key stats
- Material: Sponge rubber
- Thickness: 3.6mm
- Density: 706 kg/m³
- Impact noise reduction: 23 dB
- Tog: 0.55
Additional benefits
- Excellent flooring support ✔
- Integrated moisture barrier to protect against damp ✔
- Flooring lifetime guarantee ✔
- Ideal for uneven subfloors ✔
- Compatible with underfloor heating ✔
2. Duralay Silentfloor Gold 4.2mm Underlay
For use with floating wood and laminate floors, this sponge rubber underlay is one of the most effective acoustic wood and laminate options available, as you’d imagine with a name like SilentFloor Gold.
With an impact noise reduction of up to 24 dB, it can decrease in-room noise by up to 30%. But that’s not all. Its density rating of 710 kg/m³ will increase the lifespan of your laminate, while the in-built DPM protects against rising damp.
Key stats
- Material: Sponge rubber
- Thickness: 4.2mm
- Density: 710 kg/m³
- Impact noise reduction: 24 dB
- Tog: 0.33
Additional benefits
- High-density for ultimate flooring support and durability ✔
- Integrated moisture barrier to protect against damp ✔
- Compatible with underfloor heating ✔
- Flooring lifetime guarantee ✔
- Ideal for all areas ✔
3. Woodtex Silver 3mm Underlay
For use with floating wood and laminate floors, Woodtex is a sponge rubber underlay that offers impact noise reduction of up to 20 dB.
Although it doesn’t have quite the same level of sound insulation as the two Duralay products featured above, it’s low TOG rating of just 0.32 makes it an excellent choice for underfloor heating systems, while the higher 713 kg/m³ density rating and thinner 3mm profile will create an excellent base for any installation.
Key stats
- Material: Sponge rubber
- Density: 713 kg/m³
- Thickness: 3mm
- Impact noise reduction rating: 20 dB
- Tog: 0.32
Additional benefits
- Ultimate flooring support ✔
- Perfect for underfloor heating systems ✔
- Flooring lifetime guarantee ✔
- Ideal for all areas ✔
- Extremely dense and stable ✔
Acoustic underlay checklist
Find the best acoustic underlay for your needs by following this checklist:
- Work out whether you need to reduce impact noise, airborne noise, or both
- Look for a high-impact sound reduction rating (over 40 dB for carpets, over 20 dB for wood/laminate)
- Make sure the underlay you choose is compatible with your flooring type
- Opt for thicker underlays for better sound insulation (11mm+ for carpet and 3mm+ for wood/laminate)
- For wood/laminate or areas prone to dampness (like concrete subfloors), choose underlay with a built-in moisture barrier
- Go for durable materials in high-traffic areas to ensure long-lasting performance
Need help choosing the right underlay?
By understanding the kind of noise you’re dealing with and choosing the most effective acoustic underlay for your flooring type, you can create a much quieter home environment – and say goodbye to the elephants!
If you’re still unsure what the best underlay for your project would be, please contact our expert team at contact@simplyunderlay.co.uk. We’ll be more than happy to help.