Electric under floor heating - is it really that expensive to install??

[Rebecca]

Hiya,

We are about to start having some work done at home and thought underfloor heating might be a bit of special touch in our 2.2x2.8m bathroom. When we were discussing the possibility with the builders the actual cable mat was initially estimated at about =A3300 (which I saw priced in their supliers brochure).

They are now telling me that supply and fitting will be a total of =A3750!! =A3400 to fit? This has come as quite a surprise (to put it mildly!) and we are now reconsidering.

It will be in a new bathroom so there will be no upheaval of tiles/ flooring will be involved. All wc/ vanity will be wall hung so no awkward shapes to work around.

How long should installation take? (from what I understand the cable mat is placed directly underneath the tile grouting - tiling is seperate).

Is this a realistic price?

Thanks in advance Louise

[Roger Mills]

The matting itself shouldn't take long to install - but what is going to power it? I assume that wiring will be required, back to the meter - plus appropriate controls etc. Does the installation cost include these?

Quite apart from the installation cost, have you considered the *running* costs? It presumably needs peak rate (as opposed to off-peak) electricity? If you've got gas central heating elsewhere, it would be a lot cheaper to extend that rather than going for electric under-floor heating.

[Dave Liquorice]

You can't pump much power into underfloor heating otherwise the floor gets to hot... Electric underfloor heating mat comes in something at 150 to

200W/m^2, the OP has just over 6m^2 of floor (I wouldn't heat under the bath so maybe only 4m^2 exposed?), so 1.2kW at the top end.

But is this going to be just comfort heating or going to be the space heating as well. Comfort heating can be switched on/off as required, though the thermal inertia of the tiles might mean it having to be switched on a hour or two to before one took a bath.... Space heating would need to be on nearly all the time particulary in the cooler periods of the yera and running costs would be rather high.

Extend as a conventional radiator or wet underfloor? The latter is not as simple as it might first appear, radiator water is at 70 to 80C the return

10C or so lower both are too hot to stand on... I think you'd need to put in a heat exchanger and have another low temperature circuit for the UFH.

[Rebecca]

Thanks. Just to clarify it is comfort heating - we have a towel rail radiator too. Are those costs justifiable?

Louise

[auctions]

It depends on how much wiring is needed outside the bathroom to get a suitable supply. The fitting of the mat is quick and easy - abaout 2 hours tops.

Materials should be less than that too - I'd expect about =A3150 for the mat maximum. I use

You'll also need undertile insulation and a thermostat/programmer. Your builder should get a trade discount off the prices too.

A

[Roger Mills]

Either - but I really had a conventional radiator in mind. Wet under-floor would be a closer match to what the OP wants to achieve, but starts to get more complicated (and expensive!) to implement.

[The Natural Philosopher]

Seriously Louise, if its a new install and you just want warm feet, lift the floor and rub some CH pipes under it. Typically if you put in a water heated towel rail and make the pipes wander a bit around the underfloor space, that will do he trick.

[Rebecca]

and the wiring and controls needed. No room in floor for CH pipes. I dont mind spending abit, but we had been led to believe it would be =A3500 at the very most.

Thanks Louise

[Adrian]

Rebecca (Rebecca ) gurgled happily, sounding much like they were saying:

Sounds high to me.

I fitted electric underfloor (as a comfort thing in association with a towel rail rad, as yours) in a small shower room a couple of years ago.

so we'd got power in there already thanks to a silly little ioniser thing that had been there before - but if yours is indeed a "new bathroom", a supply's not going to be that difficult to arrange.

IIRC, the mat was less than £100 and the controller (we went for the digital thermostatic timer) was about the same. If it'd been much more, we probably wouldn't have bothered. Fitting was very straightforward - paint on the insulator goop, tape down the wires, wire the controller in

- then tile. Works beautifully. We set the timer to switch it on between about 5am and 8am, so the floor's toasty for morning showers.