Carbon underfloor heating, layer by layer.

In two sentences

Carbon underfloor heating is electric surface heating: a layer of carbon heats up when current passes through it, and gives off that heat by radiation. The one we fit is the IREWA system, from the German manufacturer Carbon Heizsysteme: its film heats across its whole surface, not along a cable.

What is in the 5 mm

Three layers, laid one on top of the other on your floor. The values are the manufacturer’s.

Your floor covering goes on top: wood flooring, vinyl or laminate, tiles. No screed, no pipes, no manifold: the fitting without screed page gives the finished height for each floor covering.

What heat it gives

• Supply. 230 V, with no transformer. One thermostat per room.
• Output. 115 W/m² in living areas; 180 W/m² in a tiled bathroom, because a mat or a dry screed then separates the film from the tiles.
• Temperatures. 32 °C at most in the film at 115 W/m², 44 °C at 180 W/m². At the floor surface, in service: 20 to 24 °C.
• Warm-up. Warm feet in about a quarter of an hour; from 17 to 21 °C in the room in 30 to 45 minutes, depending on the building. There is no screed to heat first.

The film’s data sheet, dated 2024, gives 0.4 mm, 35 °C at most and a carbon layer over more than 85% of the surface. The values above are those the manufacturer publishes on its website today.

Why “full-surface” matters

Very different products are sold under the name of carbon heating: striped films, fleeces, paints, and films coated over their whole surface. On a striped film, only the stripes heat; between them, the film stays cold.

The manufacturer draws a simple argument from this: the larger the surface that heats, the more it can stay warm rather than hot, and the less time the heating runs. That is also what the thermal camera check shows at the end of the job: the whole floor lights up, with no coil pattern. The page carbon heating film: the differences compares the four families.

Main heating, or supplementary?

The system is designed as the only heating in the home, and sized room by room: we cover 75 to 85% of the floor area of each room, everything that is not under fixed furniture. The rule in your country then decides. In France, we have found no text that stands in the way in an existing home. In Wallonia, Flanders, Luxembourg and the Netherlands, a text limits direct electric heating or rules it out as main heating: what each country allows. The manufacturer publishes the consumption read at the meter in eleven buildings: the figures are on the measured consumption page.

What the system does not do

• It does not heat water. Hot water needs a separate water heater.
• It is not laid in the shower or under fixed furniture, or under a bath.
• It does not make up for an uneven floor. Beyond a deviation of 2 mm over one metre, a levelling compound is needed first.
• Without electricity, it does not heat: like a heat pump, or a boiler and its circulation pump.
• It does not qualify for any of the grants we have reviewed, which fund a heat pump: MaPrimeRénov’ in France, Mijn VerbouwPremie in Flanders, Klimabonus in Luxembourg, ISDE in the Netherlands. The details, country by country, are in the frequently asked questions.
• In a new build, the project’s energy calculation decides whether it fits.
• It is not allowed everywhere as main heating. Three of the four countries where we fit limit direct electric heating: the rule, country by country.

These limits, and the others, are brought together on the drawbacks page.

Who fits it

Carbosol is an official IREWA partner: we design, supply and fit, with our own teams, in France, Belgium, Luxembourg and the Netherlands. The electrical connection is made by a qualified electrician, to the standard of the country.

The job is described on the page fitting, step by step; the checks and the warranty, on the page warranty and certifications.

To get a price range for your floor area: describe your project, or call.

Updated on 9 October 2026.