Best Carpet Underlay UK 2026: Six Options Compared
Share
X
Copy Link
The best carpet underlay for most bedrooms and living rooms is a resilient 9–11mm product that balances comfort with support. Our overall pick is Cloud 9 Cumulus 11mm: its published 3.1 tog and 43dB impact-sound figures make it a strong choice when warmth and comfort matter. It is not the right answer over underfloor heating, where a low-tog specialist underlay such as Duralay Heatflow is the better fit.
Do not choose by thickness alone. Density, construction, thermal resistance, acoustic performance, carpet type and fitting method all matter. A very soft 12mm foam can suit a bedroom but be awkward on stairs, while dense crumb rubber is firmer and better suited to demanding areas.
Our top pick
Cloud 9 Cumulus 11mm
Cloud 9 Cumulus offers a convincing all-round combination of warmth, cushioning and noise reduction for general domestic rooms. Choose Duralay Heatflow instead for underfloor heating, Plushwalk 8mm for stairs, or Durafit 650 where durability and firm support matter more than a deep, soft feel.
Best carpet underlay UK: six options at a glance
| Product | Construction | Thickness | Published tog | Published sound reduction | Best for |
|---|---|---|---|---|---|
| Cloud 9 Cumulus | PU foam | 11mm | 3.1 | 43dB | Best overall |
| Plushwalk 12mm | PU and viscoelastic foam | 12mm | 3.5 | 49dB | Bedrooms and maximum cushioning |
| Plushwalk 8mm | PU and viscoelastic foam | 8mm | 3.0 | 40dB | Stairs and tighter floor transitions |
| Duralay Heatflow | Sponge rubber | 6.1mm | 0.75 | 31dB | Underfloor heating |
| Super Velvet | Felt and crumb rubber | 12mm | 3.0 | 48dB | Sound reduction and wool carpets |
| Duralay Durafit 650 | Reinforced crumb rubber | 6.5mm | 1.1 | About 28–29dB | Heavy traffic and double-stick fitting |
On a phone, swipe the table sideways to compare every column.
How we chose these carpet underlays
We selected six genuinely different products rather than six similar foam rolls. We compared construction, thickness, published tog and impact-sound figures, intended use, roll coverage and fitting method. Product specifications were checked against current manufacturer data where available, and each exact Amazon UK listing was available when checked.
We have not hands-on tested these underlays. Published laboratory figures help compare products, but the finished result also depends on the carpet, subfloor, room, installation quality and whole floor build-up. Confirm the exact roll and specifications before ordering, particularly where underfloor heating, contract use or a specialist fitting method is involved.
Best overall
1. Cloud 9 Cumulus 11mm carpet underlay
A warm, comfortable all-rounder for bedrooms and living rooms. Cumulus is an 11mm PU foam underlay supplied here as a 15m² roll. Cloud 9's published data gives it a 3.1 tog rating and 43dB impact-sound reduction, so it prioritises warmth, cushioning and domestic comfort.
The high tog rating also defines its main limitation: it is a poor match for underfloor heating. It is best used beneath a compatible carpet in a normally heated room, with the fitter checking door clearance, gripper height and the carpet manufacturer's requirements.
Choose it ifYou want a recognised, comfortable underlay for a bedroom, lounge or other general domestic room.
Skip it ifYou have underfloor heating or need a thinner, firmer underlay for stairs.
Main compromise: the warmth and deep cushioning come with greater floor build-up and high thermal resistance.
Best for a luxurious bedroom feel
2. Plushwalk 12mm carpet underlay
The deepest cushioning in this shortlist. Plushwalk combines PU and viscoelastic foams and this exact listing covers 15m². Wilsons publishes a 3.5 tog rating and 49dB impact-sound figure for the 12mm version, making it the warmth-and-softness choice for a low-traffic bedroom.
Thicker does not automatically mean more durable or suitable everywhere. The 12mm build-up can complicate doors, thresholds and stairs, and its high tog makes it unsuitable where efficient heat transfer from underfloor heating is required.
Choose it ifYou want a soft, warm bedroom floor and have checked all height clearances.
Skip it ifYou are carpeting stairs, a heated floor or a hard-working entrance route.
Main compromise: maximum cushioning is less versatile than a thinner, denser underlay.
Best for stairs
3. Plushwalk 8mm carpet underlay
A thinner version that is easier to accommodate around treads and risers. The 8mm Plushwalk uses the same PU and viscoelastic foam family as the thicker versions but reduces the floor build-up. Wilsons publishes 3.0 tog and 40dB impact-sound figures for this thickness.
Its thinner profile makes it the more practical Plushwalk option for stairs and tighter transitions, but suitability still depends on the carpet, grippers and fitting method. A fitter should confirm the complete stair build-up rather than selecting by millimetres alone.
Choose it ifYou want cushioning on stairs without forcing a 12mm foam around every tread and riser.
Skip it ifYou need the firmest heavy-contract support or a low-tog heated-floor product.
Main compromise: it gives up some softness and acoustic performance compared with Plushwalk 12mm.
Best for underfloor heating
4. Duralay Heatflow carpet underlay
A specialist low-tog option designed to let heat pass through. Duralay Heatflow is a 6.1mm sponge-rubber underlay supplied here as a 10m² roll. Its published figures are 0.75 tog and 31dB impact-sound reduction.
Underfloor-heating suitability depends on the complete floor, not the underlay in isolation. Add the carpet and underlay tog values, then check the combined result against both the carpet and heating-system manufacturers' limits. Do not assume that every carpet can be paired with Heatflow.
Choose it ifYou need a carpet underlay specifically designed for heat transfer over a compatible heated floor.
Skip it ifYour priority is maximum insulation in a room without underfloor heating.
Main compromise: its low thermal resistance means less insulation than a high-tog foam product.
Best for sound reduction
5. Super Velvet felt and rubber carpet underlay
A traditional combination with a strong published acoustic figure. Super Velvet pairs a felt top layer with a crumb-rubber base. Wilsons publishes a 12mm thickness, 3.0 tog rating and 48dB impact-sound reduction for the 10m² roll.
That specification makes it attractive for upstairs rooms, flats and compatible wool carpets where warmth and impact-noise reduction matter. It cannot soundproof a defective floor, stop airborne noise on its own or replace treatment of gaps and flanking paths.
Choose it ifYou want a felt-and-rubber construction with warmth and strong impact-sound performance.
Skip it ifYou need a low-profile, low-tog product or the softest foam feel.
Main compromise: the thick, substantial roll is heavier and less straightforward to handle than lightweight PU foam.
Best for heavy traffic
6. Duralay Durafit 650 crumb-rubber underlay
A dense contract product for support rather than sink-in softness. Durafit 650 is a reinforced crumb-rubber underlay intended for stretch-fit and double-stick installations. Interfloor classifies it for heavy contract use and publishes a nominal 6.5mm thickness, 415kg/m³ density and 15.07m² roll area.
This is the specialist choice for demanding routes, commercial-style durability or an installation that requires double sticking. It is heavy, firm and more product than many bedrooms need. Interfloor's data also says suitability for underfloor heating must be judged carefully and excludes electric mat or dry systems.
Choose it ifYou value dense support, heavy-use classification and double-stick compatibility.
Skip it ifYou want a light roll and a deep, cushioned bedroom feel.
Main compromise: excellent support feels much firmer than a thick PU or memory-foam underlay.
Which carpet underlay is best for each room?
Bedrooms: comfort and warmth can take priority because foot traffic is normally lower. A 10–12mm foam such as Cloud 9 Cumulus or Plushwalk 12mm can work well if the door and threshold clearances allow it.
Living rooms: choose a balance of comfort and resilience. An 11mm PU foam suits many homes, while felt-and-rubber construction makes sense when impact noise and firm support matter.
Stairs and hallways: favour a thinner, supportive underlay that can be fitted securely around stair geometry. Plushwalk 8mm is the thinner comfort choice here; dense rubber is worth discussing with the fitter for hard-working routes.
Rooms over underfloor heating: choose by combined thermal resistance, not softness. Duralay Heatflow is the dedicated low-tog option in this shortlist, but the carpet must also be compatible.
What thickness carpet underlay should you choose?
For many bedrooms and living rooms, 9–11mm is a useful starting point. A 12mm underlay can feel more cushioned, but it may raise the finished floor enough to affect doors, thresholds and grippers. Stairs commonly benefit from a thinner, firmer product that bends and secures cleanly.
Thickness is not a quality score. An 8mm dense rubber underlay can support a carpet better in a demanding area than a soft 12mm budget foam. Compare density, compression performance and end-use classification alongside thickness.
Understanding tog ratings and underfloor heating
Tog measures thermal resistance. A higher number slows heat transfer and can help retain warmth in a conventionally heated room; a lower number allows heat from an underfloor system to pass through more readily.
Always calculate the carpet and underlay as a system. A 0.75-tog underlay beneath a high-tog carpet may still exceed the heating supplier's limit. Ask the carpet retailer for the carpet's published tog value and confirm the total with the underfloor-heating manufacturer before installation.
PU foam, rubber or felt?
PU foam is light, easy to handle and comfortable. It is widely used in domestic rooms, but products differ substantially in density and recovery.
Sponge rubber provides supportive cushioning and is available in specialist low-tog versions. Crumb rubber is denser and firmer, making it useful for demanding and contract-style installations.
Felt and felt-rubber combinations suit buyers who want traditional materials, thermal insulation and firm support. Check compatibility with the chosen carpet and fitting method.
Can carpet underlay reduce noise?
Underlay can reduce impact noise caused by footsteps and movement, but a laboratory dB figure is not a promise of whole-room soundproofing. Results change with the floor structure, carpet, ceiling below, gaps and indirect sound paths.
If noise between homes is the main problem, get the floor construction assessed. Underlay may form part of the solution, but it cannot compensate for poor separation or untreated junctions by itself.
Should you replace old carpet underlay?
Replacing it is usually sensible when fitting a new carpet, especially if the existing underlay is flattened, crumbling, stained, uneven or no longer supportive. Reusing old underlay can compromise the feel and performance of the new carpet.
There are exceptions: a relatively recent, compatible underlay in excellent condition may remain serviceable. Ask the carpet manufacturer and fitter to inspect it rather than relying only on age.
Measure before ordering
Measure each room at its widest and longest points, include alcoves and doorways, and allow for cutting and fitting waste. Roll sizes differ: several products here cover 15m², while Duralay Heatflow and Super Velvet cover 10m² per roll.
Before ordering, confirm who supplies grippers, joining tape, adhesive and disposal. A full roll can be bulky and heavy, especially with rubber products, so check access and storage.
Complete the room
Underlay changes the comfort of a room, but colour and light determine how the finished carpet feels visually. Our bedroom colour schemes and living room colour schemes offer practical ideas for choosing the surrounding palette.
The bottom line
Cloud 9 Cumulus 11mm is our best all-round choice for a normally heated bedroom or living room. Pick Plushwalk 12mm for maximum bedroom cushioning, Plushwalk 8mm for stairs, Duralay Heatflow for a compatible underfloor-heating system, Super Velvet for felt-and-rubber acoustic performance, or Duralay Durafit 650 for heavy traffic and specialist fitting.
The final check belongs with the carpet and heating-system manufacturers and the fitter. The best underlay is the one that works with the complete floor, not simply the thickest roll.
Frequently asked questions
What is the best carpet underlay?
Cloud 9 Cumulus 11mm is our best all-round choice for normally heated bedrooms and living rooms because it balances cushioning, warmth and impact-sound reduction. Heated floors, stairs and heavy-traffic areas need different products.
What thickness carpet underlay is best?
About 9–11mm suits many bedrooms and living rooms. Stairs often benefit from a thinner, firmer underlay, while 12mm products need careful checks around doors, thresholds and grippers.
What is the best carpet underlay for stairs?
We favour Plushwalk 8mm from this shortlist because it provides cushioning with less build-up than a 12mm foam. The fitter should still confirm compatibility with the carpet, grippers and stair geometry.
What is the best carpet underlay for underfloor heating?
Duralay Heatflow is the specialist choice here, with a published 0.75 tog rating. Add the carpet and underlay tog values and check the combined result against the heating and carpet manufacturers' limits.
Does thicker carpet underlay last longer?
Not necessarily. Density, construction, compression recovery, room use and fitting quality are as important as thickness. A thinner dense-rubber product can outperform a soft thick foam in a busy area.
Can carpet underlay soundproof a room?
It can reduce impact noise, but it cannot fully soundproof a room. Whole-floor performance also depends on the carpet, subfloor, ceiling, gaps and indirect transmission paths.
Product availability was checked when this guide was prepared. Specifications and listings can change, so confirm the exact product and suitability before ordering.
As an Amazon Associate I earn from qualifying purchases.
Published: September 22, 2026
Sign up with Facebook
Sign up with Google
