Electric Underfloor Heating installation

Although tiles are a practical choice for any room in the home they can be cold to the touch which is why installing electric underfloor heating is a great yet easy and cost-effective way of heating your tiled floors. It is so effective you can get rid of any unsightly radiators, particularly useful if you’re short on space! Underfloor heating is a lot more cost and energy efficient (from as little as 2.36pp/hr) and there’s also a lifetime warranty on selected products giving you peace of mind for years to come.

Installing electric underfloor heating is easy enough to do and there are a range of options available when it comes to sizes and formats – so there is something to suit any project:

- Self-adhesive matt (which rolls out) available in sizes from 0.5-15m2

- Loose wire kit (that is taped down) available in sizes from 2-10m2

- Loose wire kit (laid into a self-adhesive decoupling layer) ideal for problematic floors that require a decoupling membrane. Available in sizes from 1-16m2

Remember to measure your floor beforehand and purchase the correct size wiring as you CANNOT cut the wire to fit.

You’ll also need:

- Insulation boards, using insulation boards reduces running costs by up to 50% (see the manufacturer’s guidelines), available in varying depths of 6, 10, 12.5, 20, 30 and 50mm.

- Thermostats, available in a wide variety of colours to suit any interior scheme, some models are Wi-Fi enabled allowing you to control the heating from a smartphone (some can even control the boiler and central heating too!)

- Floor Probe (usually supplied with the thermostat)

- A fully qualified electrician

- ALWAYS follow the instructions provided in the box with your chosen system.

Insulation Boards

We recommend installing Warmup or Wedi insulation boards for optimum performance. See our insulation board guide for installation instructions for different types of screed.

Different types of electric underfloor heating

Warmup DCM-Pro wire & anti-fracture mat

Cut the DCM-PRO mat to size, peel off the backing and tack in place, pressing down once aligned. Lay additional sheets as above ensuring that the castellations are aligned.

Install the heating cable at the chosen spacing, a minimum 60mm apart, also maintain a perimeter spacing of half the chosen cable spacing around the room. Install the floor sensor centrally between two parallel runs of heating cable and away from other heat sources such as hot water pipes. When installing the cable do not cross the cable over another run, over coldtails or the floor sensor. This will cause overheating and will damage the cable.

After positioning the heat mat and thermostat, make sure you are satisfied that the area is covered correctly with no overlaps and not laid where objects will be fixed above the tiles (e.g. bath, toilet, kitchen units and appliances).

Warmup Promat (which rolls out)

Warmup Promat System is ideal for installations within regular shaped areas, where the 0.5m wide mats can be quickly rolled out across the floor in parallel runs.

Install your insulation boards and get a qualified electrician to install your wiring the same as using the Warmup DCM-Pro wire (above).

When you’re ready to install your matting, roll out the Promat and position as necessary. Once you’re happy it’s in the correct position, simply walk over the mat, as you walk over the matting the pressure sensitive adhesive glue pods on the reverse will pop, securely binding the mat to the floor.

Lay the floor sensor at least 300mm away from the wall. The floor sensor should be centred between two of the heating elements and should extend a minimum of 150mm into the heated area. When securing the sensor to the floor do not cover the tip of the sensor with tape as this can result in incorrect temperature readings.

Warmup ProWire (a loose wire that is taped down)

The Warmup ProWire System is designed to suit irregularly shaped rooms and rooms with many fixtures, since the heating cable can simply be manoeuvred on the subfloor around fixtures with ease. The spacing of the cable can be adjusted to your requirements in the desired power output and to the layout of the room you are installing the system in.

Attach the double-sided tape at an approximate distance of 50mm. The tape should be laid in the opposite direction to the heating element runs, observing the 50mm perimeter from the wall. Do not remove all of the protective film at the start of the installation as you will be moving over the taped areas as you go, this will prevent the tape from becoming damaged.

In the areas where the heating wire loops a second line, the double-sided tape must be attached. Each loop should sit fully on the adhesive tape to prevent the wire from lifting and being damaged.

Do not space the heating wire closer than 700mm or further than 1000mm apart. Spacing should be kept uniform to ensure an even spread of heat across the floor.

As you pull the wire from the box, the first 3 metres is the power supply cable. At this point you will reach where the power supply joins the heating wire. This is the joint that should be secured to the floor at the start point. You can adjust the spacings between the cable to ensure your heating cable fits the room within the permitted spacings. You cannot cut the cable to fit.

Lay the floor sensor at least 300mm away from the wall. The floor sensor should be centred between two of the heating elements and should extend a minimum of 150mm into the heated area. When securing the sensor to the floor do not cover the tip of the sensor with tape as this can result in incorrect temperature readings.

Rise Underfloor Heating

Whether you require the intricate loose wire system or the quick to install roll out matting, the Rise underfloor heating range is easy to fit. See our installation videos for a simple to follow how to of the Rise range.

Electric underfloor heating installation instructions

Step 1 - Prepping the space

When using any type of electric underfloor heating ensure you first install insulation boards. There should be no voids and the board joints are taped with glass fibre tape. For waterproof applications you will need to seal the joints using a relevant sealant as per the manufacturer’s instructions. Ensure the floor is smooth, dry and dust free and then decide where your power source will come from, always get a qualified electrician to install the wiring and electrics.

Step 2 - Get a qualified electrician to complete the underfloor heating installation

Once laid onto your substrate, when using any of the above heating systems, a qualified electrician should connect up the system to the RCD and mains supply. They must test that it is operating properly and the heat mat is heating up correctly/evenly. This also includes the resistance test of the heat mat and sensor with a multimeter.

Step 3 - Finishing Touches

You now have a choice whether to cover the wires with a thin layer of self-leveller or tile direct onto the matting. If tiling directly onto the wire it’s best to use a plastic trowel to avoid damaging the wires as you work. The heater, including the termination and coldtail joint, must be wholly within the adhesive or levelling compound and not exposed.

Important considerations when installing electric underfloor heating

Once the tiling has been completed do not turn the heating on for a minimum of two weeks. Once the two weeks have passed you can turn the heating up at 5˚C per day to operating temperature. If the adhesive is forced dried before it has properly hardened, it will tend to be weak and crumbly, which could lead to the tiles lifting or cracking. Always use a flexible grout when grouting a floor with underfloor heating. We recommend using BAL Micromax3 grout, which is available in many different colours to suit your tiling project. Always consult and follow the fitting instructions supplied with the product.

Suitable tiles

Most porcelain, ceramic and natural stone floor tiles are suitable to use with electric underfloor heating systems making it a quick and easy option for heating your home. You can check whether a tile is suitable in the product description on each individual tile product page.