which trowel size

[harry]

Hi Guys,

when tiling over UFH matting and not putting self leveler over it do you use a deeper trowel, because of the thickness of the wires and to get 100% coverage I was thinking of using a 12mm, would appreciate your comments,
Harry.

[LM Ceramics]

personally i would always advise self leveling the floor when tiling over ufh for the obvious reasons and im sure the rest of the lads will back me up i would self level over the ufh then use a 10 mm notched trowel

[grumpygrouter]

Put SLC down, trowel size is less of an issue then and you have other advantages, like a flat surface to tile on to, less potential to damage your cables.....

[harry]

Thanks guys, forgot to mention the UFH will be laid on insulated boards about 10mm thick.

[grumpygrouter]

Wont make any diff to trowel size.

[harry]

No of course it wont thanks, obviously the latex slc followed by a single part flexi ?
Also not used much slc am i right to presume that you you just pour over the wires until it covers them ? and would the boards need priming first ?
Cheers Harry......

[grumpygrouter]

Yes, cover the wires with the SLC. Check out Mapei fiberplan, single part and really good stuff and suitable for UFH. Use your preferred flexy adhesive and flexy grout. Again, mapei Keraquick and latexplus is excellent for this and Ultracolor plus grout.

[harry]

Thanks Grumpy Grouter,
I was going to use Topps SLC as I get most of my stuff from there ? and do the boards need priming before the SLC goes on top,

thanks again Harry.........

Also do the UFH have to be tested before the SLC is poured on ? thanks.

[david campbell]

and checked regulary whilst tiling!

[DERBER]

If ya not slc-ing get a cheap 1/2 round plastic trowel from wickes/b&q

[Leatherface]

Sorry, cannot answer for trowel size.
I always self level : Or walk if customer does not want to pay for it

[doug boardley]

shouldn't need to prime your slc Harry, are you gonna use a solid bed trowel?

[grumpygrouter]

Thanks Grumpy Grouter,
I was going to use Topps SLC as I get most of my stuff from there ? and do the boards need priming before the SLC goes on top,

thanks again Harry.........

Also do the UFH have to be tested before the SLC is poured on ? thanks.

Insulating boards do not normally need priming, but check manufacturers and SLC manufacturers recommendations.

[bonemachine]

If ya not slc-ing get a cheap 1/2 round plastic trowel from wickes/b&q

Always a good idea to buy cheapo plastic trowel when working woth UFH. Reason being you can round off all the corners, totally removing the risk of severing the mat.

[Uheat]

Put SLC down, trowel size is less of an issue then and you have other advantages, like a flat surface to tile on to, less potential to damage your cables.....

SLC is always the best way to go as Grumpy Says.

No of course it wont thanks, obviously the latex slc followed by a single part flexi ?
Also not used much slc am i right to presume that you you just pour over the wires until it covers them ? and would the boards need priming first ?
Cheers Harry......

the SLC only needs to cover the wires roughly 4-5mm should be fine.

Thanks Grumpy Grouter,
I was going to use Topps SLC as I get most of my stuff from there ? and do the boards need priming before the SLC goes on top,

thanks again Harry.........

Also do the UFH have to be tested before the SLC is poured on ? thanks.

Best things is to have a multimeter and a installation monitor which will save you a lot of time retesting the mats. Have a look at Underfloor Heating | Installation Accessories | Uheat

[andy-p]

if its a small area say a bathroom floor you can skim over the ufh with a flat trowel with your spf or s2 adhesive , thats what i do any way.. i should add that you let it set before tiling..

[cutntile]

i would also use self leveling. if you dont want to then make sure you use a plastic trowel so you wont damage the cables

[Lucas 2]

Mebbe this is sacrilege but last summer used slc from Wickes over cables and it was damned cheap! On top, Mapei flex. Naughty?