The Lowdown on Underfloor Heating

You’ve probably heard of underfloor heating by now, and you may know a couple of households that have installed it – they probably extol the virtues on a regular basis and now you’re thinking about it yourself. If you are, here’s what you need to know.

What are the advantages?

Your friends will probably already have told you all about how there are no cold spots or freezing cold bathroom floors in the mornings.

There are also no more bulky radiators taking up space – generally a radiator takes an entire wall out of service – there’s not much else you can do there.

Underfloor heating also means that there’s no hotspots either; the heat is very uniform and gentle and because it comes from the ground, very little is wasted.

What types of underfloor heating (UFH) are there?

There’s the wet system, which uses warm water straight from the central heating. This warm water is pumped through a network of plastic pipes that are laid in a sub-floor, underneath the eventual flooring surface.

Wet UFH uses fairly low-temperature water – 40C to 65C – to achieve a floor temperature of 23C to 32C.

Electric UFH uses cables, attached to mesh mats, and these mats are laid onto the floor, connected together and then connected to the thermostat and the mains power.

Electric systems are cheaper to install, and they are shallower in profile so there’s less need to dig down into the sub-floor, but they cost more to operate in the long-run.

Where can UFH be used?

Most UFH systems are installed on ground-floors, but increasingly, newer systems are being developed that can be installed in upper floors and even in walls.

Wet UFH is more suited to floors that are under construction, so if you’re about to head off to a discount flooring depot, ask about the possibilities for heating while you’re there. Wet systems need more excavation, so installing it at the same time as a new floor is the best way forward.

Electric systems don’t need much excavation, if any, to fit in. There are even some systems that can simply be placed under rugs, which makes them ideal for upper floors.

What do I do once it’s installed?

Not a lot, especially if you have a wet system, as once the pipes are encased in the sub-floor, that’s it. You’ll need to do some prep and thinking beforehand, though.

You need to look at the rest of the house, to make sure that it’s well-insulated. You also need insulation below the pipes, so that heat is directed upwards and not into the ground below.

If you have a wet system, you’ll need somewhere for the controls to go – many UFH systems let you control each room and all the controls can be placed in one spot, usually alongside the timer.

As with any heating system, a condensing boiler will be the most efficient, but you can use pretty much any type of boiler, really.

The science bit

Your installation company will plan everything out for you, including your optimum temperatures, ceiling height, heat loss and so on. If you’re putting a wet system into an existing room, that floor will need to come up, so bear this in mind before you start.