Costs, Fuel & Suitability

Where can water fed underfloor heating go, what will it cost and can you use renewable fuels to heat it?

Can I Use A Water Fed System Beneath A Wood Floor?

Yes, in fact as the temperature is more even with an underfloor system (than radiators which only expel heat in specific areas of a room), there is less likelihood of the flooring expanding and contracting.

What About Carpet?

Yes, carpet is not a problem, but bear in mind that it will act as an insulator (or barrier) to prevent the heat from circulating as efficiently as timber boards. For the underfloor heating to be effective, the carpet and underlay should not have a tog rating of higher than 1.5.

Can I Use It Within A Concrete Floor?

If a polished concrete floor is what you’re going for, and it has yet to be laid, there is no problem using a water fed system beneath/within the concrete. If the floor has already been laid, and you are planning to lay another floor type over it, you have two options: to dig out channels to lay the pipe work, which may be disruptive and is potentially costly and can be impractical and/or unviable; or, you can lay a timber floor or sub floor on joists above the concrete floor; the pipe work will be laid between the concrete floor and the timber.

What Sort Of Fuel Can I Use?

The water in the pipes can be heated in the same way that water is heated in conventional radiators -. gas, oil, or solid fuel heated by a condensing boiler, or renewable power sources, such as biomass, solar, or ground or air source heat.

Is A Water-Fed System Cheaper To Run Than Conventional Central Heating?

In theory, yes, because the effective temperature for an underfloor heating system is lower than for conventional water central heating (typically 50°C rather than 60°C plus). Therefore, it costs less to heat the water to the optimum operating temperature.

How Much Will A Water-Fed Underfloor Heating System Cost?

Manufacturers are extremely reluctant to give ‘ballpark’ quotes, but estimates are around £18 to £28 per sq metre for systems laid in screed, which equates to £90 to £140 for a 5 sq metre system – although you would be advised to choose an electric one for such a small space. Budget around £200 to £300 to buy a 10 sq metre system.

How Much Will It Cost To Install?

Increasingly plumbers (who are cheaper than central heating engineers) are prepared to lay a water-based system, but check they have experience or certification to tackle the work. Budget £300 to £500 for a 10 sq metre area of flooring to be fitted (depending on where in the country you are located, as fitting rates will vary). Fitting the system yourself is a job only for the advanced DIYer, but we do not recommend it.

Can I Use Renewable Sources Of Energy?

Again, because of the lower operating temperature underfloor heating requires compared to conventional central heating (which makes it ideal for use with a high efficiency condensing boilers), renewable energy sources such as solar and ground source heat are more effective.