Installing Underfloor Heating Under Laminate & Wood

To install underfloor heating under laminate or engineered wood, lay Impact Plus underlay or XPS insulation boards over a clean, sound subfloor, test the foil mat, then roll it out leaving a 100mm unheated border. Tape it down and cover any exposed cable with the foil tape, fit the floor sensor under the foil, test again, and lay the floor. A qualified electrician makes the final connection through an RCD.

What you need

Our foil heating mat, a thermostat with its floor sensor, insulation underneath, and a multimeter to test the heating at each stage. Under laminate and engineered wood, use Impact Plus 6mm insulation or hard insulation boards like our XPS boards.

Aluminium Foil Underfloor Heat Mat 150W/M²

From: £19.99 Inc. VAT
£16.66 Ex. VAT

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Impact Plus Underfloor Insulation For Laminate & Wood

From: £26.99 Inc. VAT
£22.49 Ex. VAT

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XPS Underfloor Heating Insulation Board

From: £2.19 Inc. VAT
£1.83 Ex. VAT

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Digital Multimeter

£11.98 Inc. VAT
£9.98 Ex. VAT

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How to install underfloor heating under laminate and wood, step by step

1. Test the heating before you start. The mat size and wattage are on the box label. Test the mat for continuity and resistance with a multimeter and note the readings on the warranty page at the back of the manual. If the mat is the wrong size, or the readings don’t match the test results on the box label, stop and return it for the correct size. Once a mat is unrolled it becomes the installer’s responsibility and can’t be returned for a different size.
2. Prepare the subfloor. It must be clean, sound and suitable for the floor covering. Impact Plus 6mm insulation or hard insulation boards must be laid over the subfloor before you fit the heating.
3. Measure the floor. Measure accurately, allowing a 100mm or more unheated border around the edge, and check the mat is the right size for the area.
4. Lay the mat. Start as close to the thermostat position as you can. If that isn’t practical, the cold tail can be extended with a suitable electrical wire. Unroll the mat slowly, using the foil tape to hold it in place, and make sure it lies flat with the heating element not twisted or stressed anywhere. Cover any exposed cable at the sides of the mat with the foil tape provided.
5. Turn the mat at the walls. To change direction or bring the mat back on itself, cut through the foil backing. Never cut the heating cable.
6. Work around awkward areas. If the area is an irregular shape or there’s an obstacle to avoid, the mat can be cut into strips. The cable must never be taken out of its foil casing. Lay the strips in any direction, then use the foil tape to cover any exposed wire and join all the strips and runs together. Exposed wire can cause hot spots and break the earthing continuity between sections.
7. Keep the spacing. Never lay cables closer than 50mm apart. If they get too close, touch or overlap, the cable may overheat.
8. Test again. Once the heating is down, repeat the resistance and continuity test and note it on the warranty page. The readings should match the ones from step 1.
9. Fit the floor sensor. Fit the floor probe supplied with the thermostat under the foil, between two heating wires and no more than 30mm from one of them. Keep it away from anything else that could affect it, like hot water pipes. Then check the probe’s resistance to confirm it works, and note the reading on the warranty card.
10. Set the thermostat for your floor. Programme in the maximum floor temperature recommended by the maker of your laminate or wood flooring, and set the thermostat to control the floor temperature, not the air temperature.
11. Connect multiple mats and the electrics. If you’re fitting more than one mat, connect them into a suitable junction box with one spur run to the thermostat position, ready to be wired in. The system must run through a residual current device (RCD), fitted to the electrical regulations in force at the time, and all electrical connections must be made by a qualified electrician. It’s the installer’s or electrician’s responsibility to make sure the system is fitted correctly and that any other materials used are suitable for the heating.
12. Lay the floor, then test once more. Lay your laminate or wood, then test the heating again.

Installing the aluminium foil heating mat.

It can also be installed under a wooden floor.

Fitting the floor probe onto XPS insulation boards.

Testing and your warranty

You can test the heating as often as you like, but to complete the warranty it must be tested three times: before it’s laid, after it’s laid, and after the floor covering is down. Record every reading on the warranty page.

Installing under laminate and wood: FAQs

Want to know what it all costs? See our electric underfloor heating cost guide, or call us on +44 (0)1803 316060 and we’ll help you choose.