Overlay underfloor heating

[taybert]

Anyone got this? We’d be covering an existing floor which is half uninsulated concrete slab and half suspended floorboards. I know that some of the low profile systems have the pipes set within insulated boards but they’re only thin and I wondered if people generally insulate on the existing floor before laying the heating system?

I think you would do well to get views from people who have had it fitted how effective it is in the first place. We had an extension done and was traditional underfloor heating fitted in the new build but it required a massive amount of insulation in the floor under the pipes as otherwise a lot of heat is lost and it isn't fully effective. Ours abutted part of the old house but the plumber declined to fit the overlay stuff as it wasn't very effective. As it happened the underfloor in the new build was sufficient for both. You might be better looking at traditional radiators.

Thanks Marie I’ve read a few reviews and people say it works well though you treat it more like a standard radiator than normal UFH- it has quicker warm up/cool down times as it doesn’t rely on warming the screed to create thermal mass. The main reason to do it is that there isn’t enough free wall space for the number of radiators we’d need but we’d obviously want it to be at least as good as radiators given the outlay and if it can be optimised with a bit more insulation we’d do that.

The other option our plumber mentioned was to have a radiator at one end then plinth heaters (run off the central heating) with a fan for the kitchen end. I don’t like fans though and though that’s a cheaper option I think the UFH would be ideal if it’s any good!

......or there’s option 3 of course, dig out the old slab, rip up the floor and install traditional UFH. By far the longest, messiest, most expensive option!

I have overlay UFH, had no problems with it, iirc we didn't have extra insulation it was a self levelling screed, then the boards with the pipes in, then latex, then tiles.

It doesn't get that hot underfoot but it warms the room (big space/high ceiling) very comfortably and on a lower temp/on for less time than my old electric UFH.

Love UFH

I'm not a builder...but after all the discussions the overlay central heating was pretty much that. It wasn't buried in a screed. That sound like conventional UFH but laid in an existing building.

I would suggest the OP gets a specialist UFH plumber of heating company in to advise. UFH is lovely but do t get electric and it needs the capacity to heat the whole room otherwise it is too hot underfoot and ceases to be comfortable. I know from discussing with a friend with hers. I glad ours was good. It the plumber said it had to be tailored exactly to get it right

Sorry for the typos!! Doing in a tablet.

I have electric underfloor heating straight on concrete slab (ridiculous, don't do it, takes ages to heat up as most of the heat tis heating the ground below it!) and also some laid on insulating boards (so much more efficient, can feel the heat shortly after its turned on.

Then there is retro fit hot water underfloor heating, Interior designer Sophie Robinson has laid this throughout the downstairs of her house, if you go to her instagram page, she has kept one of her stories up about it. I think its 14mm high, off the top of my head.

I have wet ufh installed on suspended floorboards but did not insulated underneath. It works ok, very warm and toasty. I have a wireless thermostat which I moved to whichever room I am in. It takes half an hour longer to heat up compared with radiators. The wet ufh I have is 12mm pipes in pre grooved 14mm thick gypsum boards and it is connected to my existing central heating. I have it downstairs in my living areas which is independently zoned from my heating upstairs which are radiators based. It is sold in kit form by sq metre. It is very easy to install. Basic plumbing skills required.