Tiling

SLC or ditra Matt to tile over UFH

Anonymous user 25/02/2024 - 2.30 PM

Hi I asked the Wunda technical department if I can just use a Ditra mat only and not the SLC. They said the Decoupling membranes are fine to use, they just don't form part of their normal recommendations. They advise that it would be best to bond the Ditra mat down with the recommended tile adhesives and then use the same adhesive on top. I explained to them my main concern is cracking of the tiles. They explained that the SLC is not there to prevent cracks. But the recommended adhesives are S2 grade, which means they are highly deformable. (I don’t know what that means) They said they would recommend levelling compound because if I have cracked tile it would be easier to replace and if I want to change flooring in the future it would be easier to lift the tiles without damaging boards and pipe. So I wanted to know from professional tilers that would it be better to go with Ditra mat only or SLC only as I can only use one of them? They said using both would reduce the efficiency of their product. If we use the SLC how can we reduce the chance of cracking tiles (bearing in mind that if I use the SLC I cannot use the Ditra mat) as this is my main concern. Update— For HazelDean—— Wunda only recommend one or the other. They advised to use SLC only as long as S2 Adhesive used. However they said I can use Ditra mat only but not both

HazelDean Tiling and Bathrooms.

Rating: 4.7 out of 5

4.7/511 reviews

Cardiff

Go with a decoupling Matt. It ticks all the boxes. So firstly fix heating matt/cable down. Use flexible SLC to secure cables/levell floor. Fix Ditra matt to slc. Then tile using S1 adhesive if on concrete sub floor. Or S2 adhesive on wooden floors. You can also upgrade adhesive to fibre.

Answered25 January 2024

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Anonymous user

I would only use sutra matting if I was you. Just completed my newbuild with underfloor heating and sutra matted it all the way through. Never have any issues with sutra Matt

Answered25 January 2024

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Gkceramics

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Ashford, Kent

Firstly, make sure the substrate is suitable to tile, ie if fitting to a wood floor the timber being used is of poor quality the floor will move and will crack extra, even if ditra was used , and check its suitable and in accordance to the adhesive specifications, also priming of the floors prior to tiling to make sure the bond is good , I would only Self leveling compound if a solid concrete floor is very uneven .

Answered25 January 2024

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A Burns tiling Ltd

No reviews yet

Shepton Mallet

If the ufh,is in the screed ,then ditra stuck down with s1, then s1to fix tiles with If its electrical ufh,fix ditra first using s1,then ufh,to the ditra ,then slc ,to cover the cables , From my understanding s2, shouldn't be used directly in contact with ditra , Some floors (upstairs mainly ) are chipboard , I overboard with hardibacker 6mm,or wedi board 6mm, then ufh, then slc , then s1 adhesive , no cracking no problems ,regards Tony (Aburns tiling ltd ) if you fix ufh directly to concrete then and slc, you are going to heat the concrete before the room ,I fix wedi to the floor with s1, then ufh ,then slc the fix with s1 , obviously everything depends on how much the client wants to spend

Answered31 January 2024

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Julian Sidney Tiling

Rating: 5 out of 5

5/51 review

Harwich

Hi I would fix the Wunda boards as recommended then i would us Bal products over this. Bal rapid mat, bal flex adhesive and bal grout to enable me to pass on there 25 year guarantee. As important as all this a putting the right expansion / movement joints into the floor. If wunda floor offer a guarantee with there recommendations then you should follow that if you want any come back on cracked tiles. They would only say its fixers error and not there recommendations . British Standards say to use a uncoupling membrane under stone tiles if you choose stone and only recommend a uncoupling membrane under porcelain tiles.

Answered21 February 2024

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