Electric UFH Which SLC & which order. - Tile Advice

[littledave]

Hi all I'm after some advice. Planning to lay some Heatmat on top of Marmox 6mm boards in my Concrete kitchen floor then tile on top.

The floor has quite a substantial dip/slope probably about 10-15mm where I have removed an old larder cupboard.

I have some Uzin 152 SLC but it concerns me that it says it's cement based.

Can I lay the Marmox using tile adhesive, Heatmat then the Uzin over the top to create the level ready for tiling.

Or would it be better to use the Uzin, then the Marmox, Heatmat and cover with Latex SLC.

Also can I just use a PVA water mix to prime the bare concrete floor.

I'm trying to keep the overall build height down.

 

[Spare Tool]

Never used or heard of Uzin leveler, long as it will goto 15mm I'd use that to get your floor flat, then boards using spf tile adhesive, then ufheating, then get a decent fibre leveler to go over the wires. I'd recommend Webber or Tilemaster.
Use a dedicated acrylic primer, not pva to seal the floor first.

 

[Tile Shop]

Your best bet is to get the floor level before putting the marmox down, as bulding up the leveller over the heatmat means that you will have some areas where its thicker, warm up much slower than the thinner areas. Once the floor is levelled, put the marmox down with tile adhesive, lay the heat mat, then a further layer of SLC to encase the cables. You can then tile onto a perfectly flat surface with flexible adhesive.

As for the Uzin 152, firstly, its only suitable to a depth of 10mm, and also in the datasheet, only says its suitable for "Warm Water underfloor heating". FYI http://www.uzin.co.uk/uploads/tx_dddownloadmatrix/NC_152_PDS_GB_0415.pdf

You'd be better of scrapping it and getting something more suitable like (for example) the Tilemaster Rapid-level 30 (which can do 15mm in one hit). That would be suitable for both levelling the floor first and covering the heating cables.

And no..... do not under any circumstances use PVA Stick to a suitable Acrylic or SBR primer from the same manufacturer of the leveller you would be using (for another example, Tilemaster Prime Plus)

So from the ground up:

Concrete substrate
Primer
SLC
Adhesive
Marmox
Heat Mat
SLC (to encase the cables)
Adhesive
Tile

 

[Dan]

As above.