How much underfloor heating do I need? Your FAQs answered

Following the recent launch of our HepCalc tool, which helps you plan your next underfloor heating project, we’ve had a lot of questions about underfloor heating in general, so we sat down with our technical experts to answer them.

How does underfloor heating work?

With underfloor heating, the floor is gently heated by piped warm water (or alternatively by electric cable) and the heating energy is emitted from the floor by natural radiation. This heat is absorbed by other surfaces in the room which then also emit warmth.

The result is an all-round, more even warmth than is typically achieved by other space heating techniques.

Radiators, for example, use room air to transfer the heat, mostly by convection. This reliance on the convection of air to heat the room results in uneven warmth and higher temperatures at ceiling height compared with floor level. As radiators intrude on the usable space within a room, there is a general desire to keep them as compact as possible. As a consequence of this, the piped water has to be hotter than for UFH in order to achieve the same level of comfort for the occupants.

Which screed should be used for underfloor heating?

Any type of screed can be used, but for best performance, the liquid flowing screed is the best. It’s very strong and dense, which is ideal for underfloor heating.

The depth of screed will be different depending on which screed is chosen, as sand cement screed needs to be thicker than liquid.

Check out our underfloor heating video playlist to find out more

How much underfloor heating do I need?

This depends on the project you’re working on, which is why we created our HepCalc tool. Simply provide some details about the room you’re planning to heat and in a matter of minutes you’ll receive a list of all required materials and associated costs.

When’s the best time to lay underfloor heating?

Different underfloor heating solutions mean that an underfloor system can be installed at any time. However, it would normally be best installed during construction of the build at the first fix stage.

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Our HepCalc tool gives you a comprehensive quotation for your underfloor heating project in three simple steps.

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How long does underfloor heating take to fit?

When installed within a screed type system, pipework can normally be installed within a day, but it is dependent on the number of circuits and the size of the property.

This time factor is also similar for the floating floor systems (a floor that doesn’t need to be nailed or glued to the subfloor). However, if the underfloor heating is to be installed within a wooden joisted system, this will take longer due to extra pre-work that is required to support the panels within the floor and the notching of joists.