Underlay for underfloor heating laminate
Updated: 23 October 2026
The heating is already in the floor, or it is drawn on the plan, and the foam rolls in the basket do not mention it. Underlay for underfloor heating laminate is a thermal question first. The system is judged on how much the whole covering resists heat, and only one roll in this set prints a tog. The other four are silent. The [underlay comparison](/hub/diy-supplies/underlay) holds the five amazon.co.uk files from 19 October 2026. This page stays with heat. We did not meter a room. A qualifying purchase can earn us a commission at no extra cost to you.
The heating is already in the floor, or it is drawn on the plan, and the foam rolls in the basket do not mention it. Underlay for underfloor heating laminate is a thermal question first.
The heating is already in the floor, or it is drawn on the plan, and the foam rolls in the basket do not mention it. Underlay for underfloor heating laminate is a thermal question first. The system is judged on how much the whole covering resists heat, and only one roll in this set prints a tog. The other four are silent. The underlay comparison holds the five amazon.co.uk files from 19 October 2026. This page stays with heat. We did not meter a room. A qualifying purchase can earn us a commission at no extra cost to you.
Our top picks
| Badge | Product | Heat line | Thickness | Sound line | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  FloorPro FloorPro silver, 3 mm, 15 m² | No tog | 3 mm | No decibel | 8.0 | about £19.88 | View offer |
 AcuStick AcuStick Sonic Gold, 5 mm | No tog | 5 mm | 24 dB, no method | 7.4 | about £29.50 | View offer | |
| Alternative |  Grandismo Grandismo heating underlay, 10 m² | Tog 0.35 | Not printed | About 17 dB, no method | 7.0 | about £33.50 | View offer |
On this page
The number the system is judged on
When the heat sits under the floor covering, Quick-Step’s UK laminate FAQ asks that the total thermal resistance stays at or below 0.15 m²K/W. The EPLF bulletin of December 2022 uses the same 0.15 m²K/W ceiling when the heat is below the underlay. That total is the boards plus the sheet, not the underlay alone.
If the heat source sits on top of the underlay, the same bulletin wants the more insulating layer, so warmth does not leak downwards. These files do not describe a thick foam used as a blanket under a mat. None of the four foil foams print a tog, so you cannot show that a 3 mm or 5 mm roll sits inside 0.15 m²K/W. An unheated floor stays on the laminate underlay buying guide.
The only tog in the set
Grandismo’s heating underlay is a stated 10 m², 1 m by 10 m, at £33.50, about £3.35 per stated square metre. The bullets print tog 0.35 and about 17 dB, with no test method and no thickness. A BEAMA note defines 1 tog as 0.1 m²K/W. If that applies, 0.35 tog is 0.035 m²K/W for the sheet alone. The listing does not print that conversion, and 0.035 is not the whole floor. Add the board’s resistance before you compare with 0.15 m²K/W.
Across 124 reviews the line is 4.5. Tear reports and heat-through reports both stay. A shop page for Duralay Heatflow also quotes 0.35 tog. That is a different product. Who the sheet is for, beside the unheated picks, is on the best laminate underlay page.
On the mat or under it
Your mat’s own sheet beats a general article, and the sheets do not agree. Wickes’s Underwood file says you put no underlay on top of that mat. Heat Mat’s Combymat guidance prefers the laminate on the mat, and says any acoustic layer above it must let heat through and must be confirmed with the flooring maker. Buyer reviews that describe heat coming through are not a Wickes approval, and they are not a pass for every UK electric system.
If your manual says nothing goes on the mat except the named floor covering, tog 0.35 does not overrule it. If the manual allows a thin acoustic sheet, Grandismo is the only file here with a tog to take to that conversation. The bullets say underfloor heating, wood, laminate, LVT, vinyl, and click. They do not say electric mat or wet screed, and they give no foil-face instruction.
What not to buy for heat
Do not buy the AcuStick 5 mm roll, either 3 mm FloorPro roll, or the 2 mm white roll as a heating underlay. Their heat line is empty. AcuStick prints 24 dB and no tog. A Royale review elsewhere quotes 0.9 tog. That figure is not on the AcuStick file. If the room is unheated, the foil rolls belong on the main comparison, where price per stated square metre is the useful sum.
Common questions
What does tog 0.35 mean in m²K/W?
Tog is a thermal resistance. A BEAMA note sets 1 tog equal to 0.1 m²K/W, so 0.35 tog is 0.035 m²K/W if that definition applies to the sheet. Grandismo prints 0.35 tog and does not print the conversion or a test method. The 0.035 figure is the underlay alone, not the laminate on top of it. You still add the board maker’s resistance before you compare the floor with a 0.15 m²K/W ceiling.
Is 0.15 m²K/W the underlay or the whole floor?
For Quick-Step’s UK laminate FAQ, and for the EPLF case where heat sits underneath, 0.15 m²K/W is the total resistance of the floor covering, boards and underlay together. It is not a budget the underlay may use up on its own. Contact temperature on that Quick-Step page is 27°C. A sheet at 0.035 m²K/W can still fail the total if the boards are already close to the ceiling. The four foam rolls here print no resistance, so they cannot be checked.
Can I put a 5 mm foam roll over electric mats?
Not on the evidence in these files. AcuStick is 5 mm and prints no tog. Wickes’s Underwood file says no underlay on top of that particular mat. Other systems allow a thin sheet only if it lets heat through and the flooring maker agrees. A 5 mm foam with an empty heat line does not meet either test. Do not borrow a 0.9 tog from a Royale listing and apply it to AcuStick.
Did buyers use Grandismo on electric heating?
Yes, in the reviews on the saved file. People describe electric foil and sticky mats, with the sheet laid so heat comes through, under LVT and wood. Other reviews say the sheet tears under a knee or a pull, and one says it is not supportive enough to protect the heating. The bullets do not name your mat model. A review is a report of one install, not a compatibility certificate.
Is the 2.5 tog carpet rule the same limit?
No. Around 2.5 tog is a combined figure for carpet plus carpet underlay. Laminate over heating uses 0.15 m²K/W as a ceiling for the whole covering, not a minimum. The heating supplier or a qualified electrician commissions the mat layout. You can take Grandismo’s printed tog to them. You should not design cable spacing from a star row.
Related pages
Sources
Public UK sources and the amazon.co.uk listings compared on this page. Listings captured 19 October 2026. Updated 23 October 2026.
- BSI, BS EN 16354:2018 (retrieved 23 October 2026)
- EPLF underlay bulletin, December 2022 (retrieved 23 October 2026)
- Approved Document E (retrieved 23 October 2026)
- Quick-Step UK heating FAQ (retrieved 23 October 2026)
- Karndean UK glue-down guide (retrieved 23 October 2026)
- BEAMA floor-covering note (retrieved 23 October 2026)
- Leasehold Advisory Service (retrieved 23 October 2026)
- EGGER how to lay underlay (GB) (retrieved 23 October 2026)
- Basingstoke laminate leaflet (retrieved 23 October 2026)