Anyone here install electric underfloor heating?

[AJC]

If so, can i just have a bit of advice please.

I want to install into my en-suite, at the moment i've a chipboard floor, i have been told to put a plywood on top of this, is that correct?

And does the wood floor need an primer/paint seal?

Thank you

[twin turbo]

Yes, have been with on a few, but i sm not a profesional... Floor particleboard(?) is what we use here normaly, then primer yes(we used heydi kz, No idia what this kind of primer is called in english) then glued on the cabels, then seal all so concrete dont just flows out everywhere, and self levering fiberstrenghtned "concrete" on IT. Hope IT gives you a idia,

Also check if you need insulation under IT, so not too much heat escapes down...

What is a clipboardfloor?
Did a google search, and guess IT should be fine on IT. Important is that the floor is stable/stiff and "waterproof" so concrete dont flow TRUE(if water can flow out, so does the concrete)

[Clipper49]

Yes mate, I'm a Master Builder and run an NHBC registered building company so know a lot more about things like underfloor heating than I do about Cossys.

The reason you want ply is to stop the movement in the chipboard floor which can crack the tiles. I'd actually recommend a product called No More Ply which is a 6mm thick cement board. You can cut it with an old hand saw or they sell a tool to score it with so you can snap it. This will screw down to your chipboard and then you use a PU adhesive (sold in silicone tubes called No More Ply adhesive) to join the sheets together. I also use a little adhesive under the boards.

Once this is done lay the heating cable or matting (depending which system you chooses) on the no more ply. Tape it down and then use a latex based levelling compound over the whole floor to cover the underfloor heating. I'd recommend Mapei Renovation Screed which can be used 3-40mm in thickness.

At this stage check the resistance on the heating to make sure it will work before you tile. Now you can tile, make sure you use a flexible adhesive and grout. I'd recommend Mapei products again.

You can buy all the materials from Tile Giant which are a national company, if you want I can pm you details for a cash account that we have there which will allow you to get trade discount which will more than likely beat internet prices.

[Adamski]

Yeah Andy I'm just doing this, we're using ply then tile backer boards screwed down with screws and washers this will prevent heat loss and any fire hazards then you lay the mat, self level over that (obviously checking the mat still works via multimeter) then adhesive and tile over that.... If you buy a kit it should have primer in it...

[Darrenaf]

Hi, as mentioned above use the cement tile boards, screw them down to your existing floor and run the UFH on top of that and tile you won't have any problems doing it that way.