Advice Needed

[Part-Time Tiler]

I'm just after some advice. I'm doing someones ensuite and they are wanting under floor heating with granite tiles on the floor and wall. I know you have to use cement based adhesive and can only cut with a wet saw but should I put some self levelling compound on the floor or can I get away with laying the granite tiles straight over the UHF. An electrician is laying the UHF by the way.
Also do you have any general advice and tips on tiling with granite as never done it before.

[enduro]

I would definitely use slc as you could risk damaging the ufh when fixing the tiles. When fixing be as clean as possible, and make sure the walls can take the weight of the tiles.

[kilty55]

i would also lay slc ,after recently trying both methods the slc is the way forward for a better finish

[whitebeam]

Natural stone at 10mm thick is about 31kg m2, Whats on the walls at the moment

[asabrush]

Pouring a levelling compound ontop of the matt is by far the easiest way and the safest way so not to damage the matt.I'd always use a latex compound for ufh.Granite isn't the easiest to lay being usually very heavy.Your walls must be strong enough to hold them.I've done a few jobs where I've stripped the walls back to stud and used 15mm ply allround.An acrylic primer is a must.Go slow with your wet saw

[Part-Time Tiler]

I'm going to check the walls again tomorrow but its a fairly new house so from what your saying the granite tiles may be too heavy for the walls as mainly plastered.

[Daz]

Is this en-suite upstairs??

What floor substrate and prepping has been done prior to UFH being installed?

You may need to strengthen the floor before the UFH is laid. Definitely use a latex SLC on top of the UFH.

With regards to the walls I would be wary of fixing onto a skimmed wall and always avoid a painted surface and make sure that you get 100% addy coverage on floor and walls (might be worth back-skimming before fixing).

Tough one to take on as a "newbie".

[Part-Time Tiler]

The ensuite is upstairs and laminate down at the moment so will check again tomorrow but think it is normal floorboards underneath that. So Captain are you saying if it is a painted surface not to do it at all.

[Daz]

Painted surfaces are a no no. Remove the paint before attempting to tile, otherwise you will only be fixing to paint and not a solid substrate (does that make sense?). Fix tiles using a Single Part Flexi addy, too.

DON'T tile over the laminate! Rip it up, fix cement boards (glue and screw), then UFH, then SLC, then tiles with Single Part Flexi addy.

[Dave]

If you are going to use slc up stairs.....make sure you seal any areas that the slc will leak into.....or you will slc the ceiling as well......

[enduro]

If you are going to use slc up stairs.....make sure you seal any areas that the slc will leak into.....or you will slc the ceiling as well......

Is this from a voice of experiance....

[Dave]

Not mine no...but my bro was fitting a kitchen last week in leeds and a tiler did it up stairs on the bathroom floor.....slc was coming through the ceiling and down the walls......

common sence tells you slc will find any gaps and flow through it...

[Part-Time Tiler]

Thanks for that lads. Would I just use an ordinary sealant to prevent the slc from leaking through the floor or is there a special sealant to use.