150W/m² Electric Underfloor Heating Peel & Stick Mats – Under Tile UFH Mat

Description

Warm your tiled or stone floor from the ground up with ThermRite™ 150W/m² Electric Underfloor Heating Mats, an under-tile system built for bathrooms, kitchens and refurbishment projects where floor build-up is tight. Each mat uses a self-adhesive mesh backing for genuine peel-and-stick fixing, a single cold-tail connection for straightforward wiring, and a continuous metallic earth screen for added protection under wet-area flooring. Certified to EN60335-2-96 and compliant with the 18th Edition Wiring Regulations, the mat delivers even heat with no cold spots beneath ceramic, stone, slate, terracotta, porcelain or marble, and is backed by a lifetime warranty.

150 W/m²

Power Output

230V

Supply Voltage

3.0–4.0mm

Cable Diameter

30mA RCD

Circuit Protection Required

Lifetime

Warranty

1.0–20.0m²

Sizes Available

🔴 Qualified Electrician & RCD Required

Installation must be wired to the mains by a qualified electrician in accordance with the 18th Edition IEE Wiring Regulations and Part P of the Building Regulations. The system must always be protected by a 30mA RCD — a dedicated RCD must be fitted if one does not already exist on the circuit.

🟡 Allow the Adhesive to Cure Before Power-On

Do not switch the heating on until a minimum of 8 days after tiling, to allow the tile adhesive or levelling compound to fully cure. Test the mat for continuity and insulation resistance before, during and after installation, and record results — the floor sensor should read 9–23 ohms depending on room temperature, with a ±5% tolerance allowed on the heating element resistance.

🟡 Larger Areas Use Multiple Mats — Parallel Wiring Only

Rooms above 10.0m² are supplied as more than one mat wired together. Mats must always be connected in parallel, never in series. The heating element itself must never be cut — only the fibreglass mesh carrier can be trimmed to turn or reposition the mat, and loose cable runs must be kept at least 50mm apart.

🟢 Floor Sensor Placement

The thermostat floor sensor must be run centrally between two heating cable runs, ideally inside a sealed sensor tube, so it reads an accurate average floor temperature. In bathrooms, mount the thermostat itself outside the wet area, as close to the heated floor as possible.

True Peel-and-Stick Fixing

The mat's self-adhesive mesh backing bonds directly to primed subfloors, removing the need for staples — which the manufacturer prohibits, since a misplaced staple can pierce the heating element. This cuts fixing time significantly versus loose cable systems.

Earthed for Wet-Area Safety

A continuous metallic earth screen runs the length of the twin-conductor cable, giving an extra layer of protection that supports safe use in bathrooms, wet rooms and kitchens when correctly RCD-protected.

Ultra-Slim Build-Up

At roughly 3.0–4.0mm cable diameter, the mat adds minimal height beneath tile adhesive — ideal for refurbishments where raising the finished floor level isn't an option.

Single Cold-Tail Connection

One cold lead per mat simplifies the run back to the thermostat or junction box, reducing the number of joints and potential fault points compared with multi-cable systems.

Flexible Modular Layout

For areas over 10.0m², multiple mats are supplied and wired in parallel, letting the heated area follow an irregular room shape rather than being limited to one mat run.

Even, Cold-Spot-Free Heat

Consistent element spacing across the mesh backing spreads heat evenly across the floor, avoiding the hot and cold banding that can occur with hand-clipped loose cable.

Electrical

Power output

150 W/m²

Supply voltage

230V, 50Hz

Circuit protection

30mA RCD (mandatory)

Cable diameter

Approx. 3.0–4.0mm

Cable construction

Twin conductor with continuous metallic earth screen

Connection

Single cold-tail lead per mat

Performance & Compliance

Product standard

EN60335-2-96

Wiring compliance

18th Edition IEE Wiring Regulations, Part P of the Building Regulations

EMC

Electromagnetic compatibility safe

Minimum cable bend radius

25mm

Installation

Suitable floor finishes

Ceramic, stone, limestone, slate, terracotta, porcelain, marble

Suitable substrates

Insulation construction board, concrete, existing tile surfaces

Minimum loose-wire spacing

50mm

Minimum cure time before power-on

8 days after tiling

Mat wiring configuration

Parallel only — never connect mats in series

Thermostat

Floor sensor thermostat required (sold separately)

Warranty

Warranty

Lifetime

Area	Total Power	Mat Length	Current Draw
1.0m²	150W	2.0m	0.65A
1.5m²	225W	3.0m	1.0A
2.0m²	300W	4.0m	1.3A
3.0m²	450W	6.0m	1.9A
4.0m²	600W	8.0m	2.6A
5.0m²	750W	10.0m	3.3A
6.0m²	900W	12.0m	3.9A
7.0m²	1050W	14.0m	4.6A
8.0m²	1200W	16.0m	5.2A
9.0m²	1350W	18.0m	5.9A
10.0m²	1500W	20.0m	6.5A
11.0m²	1650W	22.0m	7.15A
12.0m²	1800W	24.0m	7.8A
14.0m²	2100W	28.0m	9.1A
15.0m²	2250W	30.0m	9.7A
16.0m²	2400W	32.0m	10.4A
18.0m²	2700W	36.0m	11.7A
20.0m²	3000W	40.0m	13.0A

Can I cut the heating mat to fit an odd-shaped room?

The heating element itself must never be cut. You can trim the fibreglass mesh carrier and lift loose sections of cable to reposition around obstacles, but the cable runs must stay at least 50mm apart and never cross or touch each other.

How soon can I turn the heating on after installation?

Wait a minimum of 8 days after tiling before switching the system on, to allow the tile adhesive or levelling compound to fully cure. Test the mat's resistance before, during and after installation, and never use the heating system to speed up drying.

What floor finishes can this mat go under?

It's designed for ceramic, stone, limestone, slate, terracotta, porcelain and marble, fitted over insulation construction board, concrete, or an existing tiled floor.

Is a dedicated RCD required?

Yes. The mat must always be protected by a 30mA RCD. If your existing circuit isn't already RCD-protected, a dedicated RCD must be fitted before connection.

Can this be installed in a bathroom or wet room?

Yes, the mat is designed to be safe for wet areas when correctly earthed and RCD protected. The thermostat itself should be mounted outside the bathroom, as close to the heated floor as possible, with the floor sensor run centrally between two cable runs.

How is a room larger than 10.0m² heated?

Areas above 10.0m² are supplied as more than one mat, wired together in parallel — never in series. A qualified electrician should confirm your circuit and thermostat can handle the combined load; larger loads may need an electrical contactor or a second heating zone.

BTU Calculator

BTU & WATT Calculator

Room Dimensions

Length (in m):

Width (in m):

Height (in m):

Room Type

Living Room

Bedroom

Kitchen

Bathroom

Conservatory

Hallway

Glazing Type

Single Glazed

Double Glazed

Triple Glazed

External Walls

0 Wall

1 Wall

2 Walls

3 Walls

4 Walls

Insulation Level

Poor

Average

Good (New Build)

Calculate

Required Heating

0

Watts

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