The best Carpet underlays, compared.
Top pick: FloorPro 10 mm 5 m² – Highest score in the display file, with 4.8 from 52 reviews, on a 5 m² 10 mm PU roll. Best value: SIXNEA 12 mm PU underlay – Lowest rate among the 10–15 m² foam rolls, about £3.27/m², with 4.7 from 1,686 reviews. Updated October 2026.
Carpet underlay is the resilient roll between a fitted carpet and the subfloor, usually laid inside gripper rods on a stretch-fit. Look for coverage, width, a named material, and a printed class or tog when the room needs one. Crumb rubber, sponge rubber, and felt rug pads are not in this set. Thicker is not automatically better: doors still have to clear the stack. The [carpet underlay buying guide](/hub/flooring/carpet-underlay/sub/carpet-underlay-buying-guide) sets out thickness, coverage, and what a missing class means. You buy it by the roll, then cut it to the inside edge of the gripper. A felt rug pad is not this product, and a loose rug on a polished floor is not a stretch-fit.
Carpet underlay is the resilient roll between a fitted carpet and the subfloor, usually laid inside gripper rods on a stretch-fit.
38 products checked · 62 hrs invested · +24,600 readers
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Personal buying guide
Question 1 of 2
How much floor are you covering?
The FloorPro 10 mm roll is a 1 m by 5 m polyurethane sheet at £27.50, about £5.50 a square metre, with 4.8 from 52 amazon.co.uk reviews. In this comparison it is the top pick because that score is the highest in the set, on a small roll that reviewers say suits a small room with little offcut. Underlay reviews praise easy cutting, a soft feel that still reads as a good thickness, and at least one use on stairs and a landing. The title and a bullet say it is ideal for stairs, and they also claim residential and commercial use, but no end-use class is printed. A sharp blade or scissors is mentioned as necessary for a clean cut. One trailing review in the saved listing is about carpet pilling and is not an underlay fault. Noise transfer and insulation are claimed without a decibel figure or a tog, so a heated floor is not answered by this listing.
Pros
Cons
Best for: You have a small room of about 5 m², no underfloor heating to prove, and you want the highest-scoring roll in this capture.
Less suitable: You need 15 m² from one roll, a printed wear class, or a tog that leaves room under a carpet on heating.
Specifications
Common questions
What size is the FloorPro 10 mm roll?
The listing states 1 metre by 5 metres, 5 square metres, in polyurethane foam. Colour is beige.
Does the listing prove it is stair-rated?
The title and a bullet say it is ideal for stairs. No BS EN 14499 class is printed.
The SIXNEA roll is 12 mm recycled polyurethane, stated as 15 m², with catalogue dimensions of 1100 by 137 by 1.2 cm and a listed weight of 14 kg. The shelf price is £48.99, about £3.27 a square metre, the lowest arithmetic rate among the 10–15 m² foam rolls in this set, and the amazon.co.uk line is 4.7 from 1,686 reviews. In this comparison it is the best value pick: a full-size domestic roll at that rate, with the largest review count here, though its score sits below the FloorPro 10 mm top pick. Reviewers describe a boxed roll that was easier to handle, a springy thick feel, and a price below carpet-shop underlay. Hard nubs from the recycled material come up as a criticism, one person tore the sheet in a couple of places while laying about 9 m² alone, and 12 mm can be too thick under a carpet that is already fitted. The title says UK manufactured, which is a title claim rather than a checked factory test. No tog and no end-use class are printed.
Pros
Cons
Best for: You want about 15 m² of 12 mm PU at the lowest rate in this full-roll group, and the doors can take the extra height.
Less suitable: You need a printed tog, a stair class, or a smoother sheet than recycled foam with hard nubs.
Specifications
Common questions
How thick is this SIXNEA roll, and what area does it cover?
The listing states 12 mm and 15 square metres. Catalogue dimensions are 1100 x 137 x 1.2 cm and the stated weight is 14 kg.
Does the listing give a tog rating or a British Standard class?
No. Tog and an end-use class are not in the listing. The title says UK manufactured.
The 247Floors roll is 10 mm polyurethane, stated as 11 m by 1.37 m and 15.07 m², at £54.95, about £3.65 a square metre. The amazon.co.uk line is 4.7 from 571 reviews, and the catalogue weight is 10 kg. Reviewers often say it feels softer and warmer than a previous underlay, including one bedroom comparison with 7 mm, and several say it cost less than a carpet-shop roll. A long fitting review says to lay the blue surface facing down, staple inside the gripper, and trim to the inside edge, and the same review says a Stanley knife ripped lumps out while scissors were easier. Other reviews mention hard bits, though one buyer did not find them, and another warns of deep indentations under movable furniture. The catalogue width of 152 cm does not match the 1.37 m bullet, and the shape field says round while the size bullet describes a rectangular roll. Insulation is claimed with no tog, and the listing itself has no decibel figure.
Pros
Cons
Best for: You want a 10 mm domestic PU roll near 15 m² and you will cut it with scissors inside the gripper.
Less suitable: You have heavy furniture that you move often, or you need the width lines on the page to agree.
Specifications
Common questions
How big is the 247Floors roll?
The bullets state 10 mm polyurethane, 11 m by 1.37 m, 15.07 square metres. Catalogue weight is 10 kg and the colour is blue. The shelf price in the saved listing is £54.95.
Which face goes downwards?
A fitting review says to lay the blue surface facing down and to trim the underlay to the inside edge of the gripper. That is a review, not a printed instruction.
Royale’s listing is a 12 mm foam roll, 1.37 m by 11 m, 15 m², colour green, at £52.50, about £3.50 a square metre, with 4.7 from 354 reviews. Reviewers describe a soft thick walk, including on concrete that previously had no underlay, a warmer dining room in one report, and easy cutting with a Stanley knife or scissors. The bullets claim high sound proofing and high insulation, with no decibel figure and no tog, and they do not name rooms. The catalogue weight of 1 kg conflicts with a 15 m² 12 mm roll, so that figure is not usable. One buyer was told a density of 85 km/m³ by the supplier and bought something else for the stairs; that density is not in the technical table. On a polished floor, under a smaller loose carpet, one review says it tended to skid. Another roll arrived damaged and soiled, with ripped packaging and black dust, and one review felt small hard lumps.
Pros
Cons
Best for: You want a 15 m², 12 mm foam roll for a stretch-fit room and you will ignore the 1 kg catalogue weight.
Less suitable: You are laying stairs on the strength of a density chat, or you want it to grip a loose rug on a polished floor.
Specifications
Common questions
What does the Royale roll cover?
The listing states a 15 square metre roll, 1.37 m by 11 m, 12 mm foam, colour green. The shelf price in the saved listing is £52.50.
Is the catalogue weight usable?
The technical table says 1 kg. That conflicts with a 15 square metre 12 mm roll, so the weight is left unset.
Plushwalk is sold as 12 mm memory foam, 11 m by 1.37 m, 15 m², colour beige, model AMZ-Underlay-349, at £119.99, about £8.00 a square metre, with 4.7 from 184 reviews. The seller bullets claim a damp-proof layer, 49 dB, 3.5 tog, and a test to BS 5808:1991. Those performance figures are seller claims on the amazon.co.uk page, not an independent check in this comparison. Reviewers often say a cheap or thin carpet feels much softer, and several say the higher price was worth it for underfoot feel, warmth, and sound muffling. One review needed three deliveries before an undamaged parcel arrived, and another buyer expected one continuous piece on a roll. A grid pattern is mentioned as a cutting aid, and a seller reply suggested spray adhesive. At a claimed 3.5 tog the sheet is already high if you add a carpet tog for underfloor heating, and the listing does not discuss heating. The catalogue weight of about 1 kg and dimensions of about 1.1 by 0.14 by 0.01 cm conflict with the 15 m² bullet and are left unset.
Pros
Cons
Best for: You want the softest-feeling 15 m² roll in this set for an unheated room and you have compared £119.99 with the foam rolls near £50.
Less suitable: You have underfloor heating, or you need a catalogue weight that matches a 15 m² roll.
Specifications
Common questions
What specification does the seller print?
The bullets state 12 mm memory foam, 11 m by 1.37 m, 15 square metres, a damp-proof layer, 49 dB, 3.5 tog, and a test to BS 5808:1991. Those performance figures are seller claims. The shelf price in the saved listing is £119.99.
Is the catalogue weight the roll weight?
The technical table says about 1 kg and dimensions of about 1.1 x 0.14 x 0.01 cm. That conflicts with the 15 square metre bullet, so weight and those dimensions are left unset.
Flooring Online lists this as 12 mm foam, 10.95 m by 1.37 m, 15 m², colour red, catalogue weight 19.2 kg, model AMZ-Underlay-145, at £52.50, about £3.50 a square metre. The star line is 4.6 from 422 reviews, but the review text is the same as the 5 m² ASIN B00EZMT2NA, so you should not read those 422 reviews as a second sample. Themes in that shared text include a thick feel that makes a budget carpet more comfortable, a saving against an SCS shop price in one review, and fitters calling the quality acceptable. The same text says the foam is very easily damaged before the carpet goes down, that a first order never arrived and was refunded, and that grippers were raised by 10 mm for the extra thickness. Sound reduction and thermal insulation are claimed with no decibel figure and no tog. Catalogue dimensions of 10 by 2 millimetres conflict with the size bullet and are not used.
Pros
Cons
Best for: You want the 15 m² red 12 mm roll, model AMZ-Underlay-145, and you will keep the foam covered until the carpet goes down.
Less suitable: You are counting these stars as well as the 5 m² listing’s stars, or your existing grippers cannot be raised for 12 mm.
Specifications
Common questions
How much floor does this Flooring Online roll cover?
The listing states 15 square metres, 10.95 m by 1.37 m, 12 mm foam, colour red. Catalogue weight is 19.2 kg. The shelf price in the saved listing is £52.50.
Are the reviews separate from the 5 square metre listing?
No. The review text matches ASIN B00EZMT2NA exactly, and both lines show 4.6 from 422 reviews.
This Flooring Online listing is the smaller red 12 mm foam roll: 3.65 m by 1.37 m, 5 m², model AMZ-Underlay-143, at £39.99, about £8.00 a square metre. That rate is much higher than the brand’s 15 m² roll at £52.50, so you pay a small-roll premium for the same stated thickness. The 4.6 from 422 line and the review text match ASIN B00EZMT3NY exactly, including easy damage before the carpet is down, a missed first delivery, and grippers raised by 10 mm. You cannot treat the stars as proof that this 5 m² size was reviewed on its own. The catalogue weight of 1 kg and dimensions of 10 by 2 millimetres conflict with a 5 m² 12 mm roll and are not usable. Bullets repeat the superb sound reduction and thermal insulation claims, still with no decibel figure and no tog. Care is printed as hand wash only.
Pros
Cons
Best for: You only need about 5 m² of this red 12 mm foam and you accept the higher rate per square metre.
Less suitable: You are treating the 422 reviews as a separate test of the 5 m² size, or a 15 m² roll would cover the room for less per square metre.
Specifications
Common questions
How is this roll different from the other Flooring Online 12 mm listing?
This one is stated as 5 square metres, 3.65 m by 1.37 m, model AMZ-Underlay-143, at £39.99 in the saved listing. The other is 15 square metres at £52.50.
Can the star rating be read as a separate sample?
No. The review text and the 4.6 from 422 line match ASIN B00EZMT3NY.
This FloorPro polyurethane roll is 8 mm, 1 m by 5 m, and £25.95 for 5 m², which works out at about £5.19 a square metre. The listing is 4.6 from 59 reviews. Buyers praise easy cutting, a soft feel, and a lack of hard lumps in at least one roll, and one review used it under carpet tiles in a small hallway for more bounce. The title says it is ideal for stairs, but no BS EN 14499 class is printed, so that stair line is seller wording. One buyer who ordered 8 mm wrote that 10 mm might have been better in their case. A review title calls the colour yellow while the catalogue says beige. One buyer said the item was not effective and that a return would cost £16, without describing the fault. Sound and insulation are claimed in the bullets, with no decibel figure and no tog.
Pros
Cons
Best for: You are covering about 5 m², such as a small hallway or a short stair run, and you want 8 mm PU rather than a 15 m² roll.
Less suitable: You need a printed stair class, a tog for underfloor heating, or a full 15 m² room from one roll.
Specifications
Common questions
How does this differ from the FloorPro 10 mm roll?
This listing is 8 mm thick, still 1 m by 5 m and 5 square metres, also polyurethane foam. The price in the saved listing is £25.95.
Is a stair use printed, or only a class code?
The title says ideal for stairs. No BS EN 14499 class is printed. One buyer wondered whether 10 mm would have been better.
Grandismo’s roll is 12 mm PU foam, 1.37 m by 7.3 m, covering 10 m² at £39.50, about £3.95 a square metre, with 4.5 from 51 reviews. Reviewers mention a lower price than a carpet shop, a quick lay, and a thick feel under a carpet or a rug, including one shed-office floor. The bullets claim two non-woven backings and a reduction in acoustic and impact noise, but they print no decibel figure and no tog. A customer question about underfloor heating is unanswered in the saved listing, so you cannot treat the thermal line as a heating approval. One order arrived as two cut pieces rather than one length, and reviews mention the odd harder lump of foam. Colour and catalogue weight are not stated. At 10 m² it sits between the 5 m² FloorPro rolls and the 15 m² sheets if your room is in that middle band, though a 12 mm stack still has to clear the doors.
Pros
Cons
Best for: You need about 10 m² of 12 mm PU in an unheated room and you can check the door clearance before you order.
Less suitable: You have underfloor heating, or you need one continuous length rather than a roll that might arrive in two pieces.
Specifications
Common questions
What area does the Grandismo roll cover?
The bullets state 10 square metres, 1.37 m by 7.3 m, 12 mm PU foam, with two non-woven backings claimed. The shelf price in the saved listing is £39.50.
Can it be used with underfloor heating?
The saved listing asks that question and does not answer it. No tog is printed.
SnugStep is 12 mm polyurethane, 11 m by 1.37 m, 15 m², colour purple, catalogue weight 15 kg, at £52.50, about £3.50 a square metre, with 4.5 from 39 reviews. Reviewers who liked it mention easy cutting, a bouncy feel, and a bedroom laid by one person, and one fitter compared the feel with a well-known foam brand without naming a model you can match. Two reviews call it lumpy and bare in places, with lumps of solidified foam, and say it is not luxury as the title states. One review says the same product was sold about 30 percent cheaper under other brands. The bullets claim high sound proofing and insulation, with no decibel figure, no tog, and no end-use class, and a customer question about rugs is unanswered. Catalogue dimensions of 137 by 37 cm conflict with the 11 m size line, so the size bullet is the roll to use. Care is printed as hand wash only.
Pros
Cons
Best for: You want a purple 15 m², 12 mm PU roll at £52.50 and you will check the sheet for hard lumps before the carpet goes down.
Less suitable: You are buying the word luxury on the title, or you need a tog and an end-use class on the listing.
Specifications
Common questions
What size is the SnugStep roll?
The bullets state 12 mm polyurethane, 11 m by 1.37 m, 15 square metres, colour purple, catalogue weight 15 kg. The shelf price in the saved listing is £52.50.
Do the reviews agree it is a luxury foam?
Several reviews praise the thickness and bounce. Two say it is lumpy or bare and not luxury, with solidified foam in the sheet.
The FloorPro polyethylene roll covers a stated 15 m² at £25.99, about £1.73 a square metre, and the amazon.co.uk line is 3.9 from 83 reviews. Reviewers who wanted a basic layer often mention the low price and how light the roll is to handle. Thickness does not settle: the title says 7 mm, the catalogue says 6 mm, and one buyer measured 5 mm. Several reviews describe a ribbed or corrugated face rather than a flat sheet. One report says half a roll arrived melted, with holes through the foam. A fitter’s review says the sheet is not for cushion-floor vinyl and that it damaged a vinyl floor. The bullets name Barrier Pro X joining tape, but the product data do not say the tape is in the box.
Pros
Cons
Best for: You want the cheapest stated area in this set and you have already accepted a thin polyethylene sheet under carpet.
Less suitable: You need a flat PU cushion, a single agreed thickness, or a layer under vinyl cushion flooring.
Specifications
Common questions
Is this the same foam as the FloorPro PU rolls?
No. The material line says polyethylene foam, and the bullets call it a low-cost budget underlay. The shelf price in the saved listing is £25.99 for 1 m by 15 m.
How thick is it?
The title says 7 mm, one bullet says 6 mm, another says 7 mm, and the catalogue thickness is 6 mm. A review measured 5 mm. There is no single figure.
Eleven amazon.co.uk foam rolls were compared from listing files captured on 19 October 2026. There is no separate scoring note for this comparison. The top pick and the best value are the awards already on the display file. The five weights below follow the buying order in the digest and sum to 100. This is not a laboratory wear test, and a star rating is not a wear class.
Material and thickness
25%Whether the roll is polyurethane, polyethylene, or memory foam, and whether the stated thickness is one figure you can use against doors, nosings, and stairs.
Coverage and roll size
20%Stated square metres and the width and length, so a 5 m² roll is not treated as the same buy as a 15 m² roll.
Printed class, tog, and sound
20%A BS EN 14499 class, a tog, or a decibel figure only when the listing prints one. A bare sound-proofing line is not Approved Document E.
Amazon reviews
20%The amazon.co.uk star line and review count, plus review themes already in the display file. Shared review text is not counted as two samples.
Price per square metre
15%Shelf price divided by the stated coverage. The figure is arithmetic, not a fitted quote.
Match the roll to the room before you compare the shelf price. A cold bedroom can take a thick polyurethane sheet. Stairs and a hallway need density and a class, which these listings mostly omit. Underfloor heating is a tog decision, not a thickness decision. The eleven prices below are the amazon.co.uk shelves on 19 October 2026, from about £25.95 to about £119.99. Per-square-metre figures are arithmetic, not fitted quotes.
Carpet underlay is the resilient roll between a fitted carpet and the subfloor, usually laid inside gripper rods on a stretch-fit. You buy it by the roll, then cut it to the inside edge of the gripper. Joining tape and gripper are separate. A felt rug pad is not this product, and a loose rug on a polished floor is not a stretch-fit. In this comparison the material is foam.
A thick foam feels soft in a bedroom. Stairs and hallways need density and a class, which these listings mostly omit. “Ideal for stairs” on the FloorPro bullets is seller text, not a BS EN 14499 class. Heating needs a tog. A 12 mm comfort roll can be the wrong buy on a heated floor.
Approved Document E in England sets a maximum impact sound L'nT,w of 62 dB for purpose-built separating floors. That is the floor, not the roll. A printed decibel figure, including Plushwalk’s seller 49 dB, is not that test. Most rolls here print no decibel figure at all.
Lay the sheet inside the gripper and trim to the inside edge. Do not overlap seams, and do not cover the gripper. A rug pad is not a stretch-fit underlay. A catalogue weight of about 1 kg on a 15 m² roll is not the true roll weight.
Name the foam before you compare thickness. PU rebond is light and cushioned. In this set that is SIXNEA, both FloorPro PU rolls, Grandismo, Royale, Flooring Online UK, SnugStep, and 247Floors. FloorPro B08JKMM5GY is polyethylene, a budget sheet, with 7 mm in the title and 6 mm in the catalogue. Plushwalk is sold as 12 mm memory foam. Crumb rubber is heavy and firm, and it is the trade default for recovery under furniture and on many stairs.
Rolls here are about 5 m² (1 m wide), 10 m², or 15 m² (often 1.37 m wide). Buy joining tape and gripper separately. A 5 m² roll at a low shelf price can still be dearer per square metre than a 15 m² roll. Flooring Online’s 5 m² 12 mm sheet is about £8.00/m², against about £3.50/m² on that brand’s 15 m² roll. SIXNEA is about £3.27/m². The FloorPro polyethylene roll is about £1.73/m² and it is not a PU. Prefer a BS EN 14499 class, such as GD/U, L/U, or HC/U, over a bare “tested to BS 5808” line.
Three typical situations, each with a recommendation from this comparison.
You are covering about 5 m², with no underfloor heating to prove, and you want the highest-scoring roll in this capture. The FloorPro 10 mm polyurethane sheet is about £27.50, with 4.8 from 52 reviews. No end-use class or tog is printed.
You want a full domestic roll and the doors can take 12 mm. The SIXNEA recycled polyurethane roll is about £48.99 for a stated 15 m², about £3.27 a square metre, with 4.7 from 1,686 reviews. Hard nubs and a missing tog are the limits.
You have already accepted a thin polyethylene sheet under carpet. The FloorPro PE roll is about £25.99 for a stated 15 m², about £1.73 a square metre, with 3.9 from 83 reviews. The title says 7 mm and the catalogue says 6 mm.
The top pick is the FloorPro 10 mm polyurethane roll, about £27.50 for 5 m². The display file gives it the highest score in the set, with 4.8 from 52 reviews, on a small roll that reviewers say suits a small room. No end-use class, tog, or decibel figure is printed, so the stair line stays seller wording. The best value is the SIXNEA 12 mm recycled PU roll, about £48.99 for 15 m², about £3.27 a square metre, with 4.7 from 1,686 reviews. Hard nubs and the missing tog are the limits. Neither award is a laboratory test.
FloorPro 10 mm 5 m²
Highest score in the display file, with 4.8 from 52 reviews, on a 5 m² 10 mm PU roll.
SIXNEA 12 mm PU underlay
Lowest rate among the 10–15 m² foam rolls, about £3.27/m², with 4.7 from 1,686 reviews.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources listed in the research digest. Listing prices, stars, and review counts are from amazon.co.uk on 19 October 2026.
This page contains affiliate links to amazon.co.uk with the tag pcuk26-21. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars, and review counts are the UK listing lines from 19 October 2026. We did not run a lab test.
