We are looking at getting an extension put on to our house. Thinking of putting underfloor heating in downstairs, anyone got any (good) advice. We are still to get the boiler checked out that it can cope, but should be fine…the new build should be much more thermally efficient that the original building. have anyone used electric floor pads? Floor is suspended and think we can use a metal pan dropped between the joists.

Any advice would be welcomed to give us a stear. The architect is looking at ideas just now as well.

Have a look at the polypipe systems. I see a lot of underfloor heating go down.( I’m a chippy) and this will be the one I’ll eventually use.

http://www.polypipe.com/building-products/plumbing-heating/underfloor-heating/
Their overlay system is v good, easy and relevantly hassle free .

Used lots of underfloor, steer clear of electric mats systems.

Have used mainly David Robbens who are very good, Uponor who have been ok, and have recently had some dealings with Nu Heat who have impressed me with their help so I will be interested to see how their system works when we install it.

Make sure you get someone who knows how to install and design it properly though. Too many people just put pipe in at whatever centres with little or no insulation, air gaps, even found some installed in sand for some bizarre reason. Also ensure that it is controlled independently from the other heating.

Design from the top down, so work out floor covering and the maximum surface temperature you can have, or TOG value if using carpet and underlay.

don’t rely on the builder to put it in, get it as a separate deal then?

electric mats I was thinking of keeping away but useful to have someone else say so! Not sure how independent controls will work with our boiler but will look into it.

Cheers

Nowt wrong with our electric mat system IME, obviously never going to be as efficient as hot water system but ours has been brilliant for the last 5 years. We put one into a kitchen extension, so the mat system meant we didn’t have to piss around with digging up the floor (wouldn’t have been able to afford that & ours is solid concrete) and as our boiler was ‘old’ at the time, it wasn’t a real option.

Bear, some installs suit a biscuit screed 10:1 sand and cement, thats the cheapest way of doing it in between joists. cheaper than the alu pans anyways. Problem is the weight adds approxiamtly 25kg per 1m2. Some people just use sand. it works but theres nothing binding it together.

Just don’t expect the system to work like the radiator system. We got lots of complaints from the care homes we installed into as they often expect a very reactive system …. Ie turn up the thermostat and 5mins later the room is toasty. UFH systems are a very gradual build up and have to be left on to reach optimum temp.

Have a look at Wundafloor. Various in screed and overlay systems offered and undercut the companies mentioned above by a large margin. All their stuff is covered by long warranties and the service was friendly.

Ours hasn’t been commissioned yet but happy so far

what’s the attraction / advantage of underfloor heating then? assuming you’re coming from the position of already having a house full of radiators…

what’s the attraction / advantage of underfloor heating then? assuming you’re coming from the position of already having a house full of radiators…

Not having radiators. That’s it.

warm feet. 😀 I think it will look better and provide more wall space. Someone told me that its more efficient to warm a space with underfloor than radiators as well.

If it’s a new-build would it not make more sense to have solid floors with a wet system in the screed and proper thermal insulation underneath?

our engineer advised otherwise, as the current structure is suspended, we should have suspended throughout. Something to do with losing too much ventilation under the floor as the whole of one elevation would be blocked up.

Flux

yes am aware of using it to increase thermal mass (there are boards that would have been easier to use in this case) but it was lose and not full fill, then they put chipboard floor followed by an engineered board.

Nowhere did the instructions from the company say this was ok, and the wood floor was too thick to transmit the heat properly.

I’m sure your engineer knows what he’s talking about but it’s very easy to duct through a solid floor to external air bricks and for underfloor heating which operates at relatively low temperatures you want to make sure as much heat as possible is coming up, not going down.
I know there are good systems available to work with suspended floors but they need to bit fitted well.
Not sure they would ever be as efficient as a solid floor system? Worth checking?

singlesman, thanks for the heads up. I will look into this further with the engineer, and see what we can do.

donks – Member

Just don’t expect the system to work like the radiator system. We got lots of complaints from the care homes we installed into as they often expect a very reactive system …. Ie turn up the thermostat and 5mins later the room is toasty. UFH systems are a very gradual build up and have to be left on to reach optimum temp.

That is the crux of it IMO in our very changeable climate I’m not sure UFH works that well.

I’ve laid timber floors over an interesting system from a company called Timoleon. Their Toron (their own brand name) sheets are 22mm chipboard with interlinking channels routed out for a 12mm plastic pipe. So, a suspended floor can have celotex between the joists over a ventilated void, chipboard (Toron) floor, which is then overply-ed and then covered with finished flooring. By all accounts, it works well. (IANAUFHE)

I had it installed in my extension last year.mits brilliant. The thermal lag thing is a non issue. It’s on all the time and is thermostatically controlled. I originally set it to 20 regs but that is too hot so gradually cranked it down to about 15 regs on the thermostat. Its a strange thing in that if you come in from the cold the room doesn’t feel toasty, but if you sit there for a few mins the warmth creeps up on you. We thought we’d miss a heat source like a fire, but we hasn’t so far. Go for it I’d say. Now I’d your only chance.