Using a leveling compound with underfloor heating?

[PaulJohnson]

Hi guys,

I have just had an extension built and have had underfloor heating installed in the kitchen. The pipes have been laid and a concrete screed has been put over the top.
I have primed this with Mapei Primer G to seal the dust while I get round to tiling the floor.

The problem I have is that the floor is not perfectly level. What is your advise? Should I try and make up the differences using the adhesive (bare in mind I have only tiled a floor once before) or should I use a self levelling compound.

My worries with the self levelng compund are that it is another layer between the heating and the tiles and also that it may not bond correctly with both the base and the tiles.

Any help would be appreciated.

Paul

 

[Alan.P]

Morning Paul.

How much is the floor out, what area is it and what tile type and size are you using ?

 

[PaulJohnson]

There is 22 square meters of floor and I will be using 450mm square tiles.

There is about 15mm between a high point and the next low point. However I can't tell how far out it is from the lowest dip at one end of the room to the highest point at the other.

Paul

 

[Alan.P]

MMmm, you don't really want to be packing that amount out over that area, you would be better off with a slc, there are several that go to that thickness in one hit, so that you get a better idea of low spots, and amount of them, try finding the high spot then using packers ( card / wood or whatever ) work around the room with your level placing packers every so often, you'll soon 'map' the room and be able to tell where the high and low spots are, from this you'll be able to gauge how much slc you need.

I've got to go now, someone else will be along shortly to help I'm sure, good luck.