Adhesive, mat thickness for planning floor build up

[Adam2]

This is a new build with reinforced concrete slab and hollowcore intermediate floors topped with insulation + liquid screed with UFH. Planning to tile, maybe something like a 10mm porcelain tile similar to this https://www.porcelainsuperstore.co.uk/portland-light-grey.html

 

Trying to work out the detail on levels for the screed quotes. At the moment I have (fairly generic info from the architect):

Floor finishes 25mm

Screed 75mm

Total 100mm

 

This seems unnecessarily thick so am thinking:

 

Tiles 10mm

Adhesive 5mm

Liquid screed 50mm

Total 65mm

 

If we also use an anti-crack mat there seems to be real variability in products from Ditra to this: https://www.protilertools.co.uk/product/kerakoll-biotex-reinforced-anti-cracking-membrane--was-idrobuild--sold-per-1m--?gclid=CjwKCAjw0On8BRAgEiwAincsHIgPgYGomuCUL6scxgllFqXruvHdKtdoCbA1fxo0u2BZ1WRtkJcUEBoCVxEQAvD_BwE

 

Which is much thinner and very cheap in comparison - any views on whether this cheaper option would be suitable - seems to say it does the same thing?

Can't see install instructions but presumably you still have adhesive 3mm + matt 1mm + adhesive 5mm + tiles 10mm

 

 

Key question - is this matt something to steer clear of = a false economy?

Are these level calcs correct, am I missing anything?

 

 

 

 

 

 

 

 

 

 

[nod]

If you are using matting Allow 6 mil The rule of thumb with floor tiling is the adhesive needs to be the thickness of your tile 

So you will need to choose your tile pretty soon 

[Adam2]

12 minutes ago, nod said:

If you are using matting Allow 6 mil The rule of thumb with floor tiling is the adhesive needs to be the thickness of your tile 

So you will need to choose your tile pretty soon 

Thanks @nod - looks like lots of 10mm tiles so hopefully a wide choice but of course my wife will find a 15mm one that has to be used after we commit to that ?

 

so 6mm adhesive + matting + 6mm of adhesive + tile or 6mm total adhesive (3mm either side of matting)?

 

As a man that knows more than most about matting - is the much cheaper and thinner Keracoll product a sensible choice in this situation?

 

cheers

 

[macglo]

Ditra matting is the tilers and most UHF companies favourite or as they call it the anti crack mat ?

[nod]

17 minutes ago, Adam2 said:

Thanks @nod - looks like lots of 10mm tiles so hopefully a wide choice but of course my wife will find a 15mm one that has to be used after we commit to that ?

 

so 6mm adhesive + matting + 6mm of adhesive + tile or 6mm total adhesive (3mm either side of matting)?

 

As a man that knows more than most about matting - is the much cheaper and thinner Keracoll product a sensible choice in this situation?

 

cheers

 

Ditra or Durabase matting work well 

Dura is slightly cheaper 

Allow 6 mil in total for the mat 

5 mil  notch float to put it down with 

  
I always tell clients to allow 35  in total It’s easy to come up a little 

[Adam2]

Thanks- the Keracoll is less than half the cost hence my question if anyone has used this. Don't mind spending more if it is justified but would like to know as there is a lot of floor area involved ?

 

so @nod apologies for asking again but I need to be 100% sure - if, as you suggested, I allow 6mm for the mat (assuming ditra which is 3.5mm I think) so the adhesive and Mat = total 6mm thick. On top of this another 8-10mm for the next layer of adhesive then 10mm for tiles so this looks to be 24-26mm - correct?

[nod]

26 will be fine if you are sure that you are using 10 mil tiles 

[wozza]

Ditra has a proven track record.

 

We used it a few weeks ago (about 2.8 rolls), I would use it again, shop around for a good price - try CTD.

I am not sure about the thin rubber / fleece decoupling matting. The shape of the Ditra offers a good mechanical fixing.

 

We used also used Kerakoll Fugabella grout for our main floor area - the tiler said it was the best non epoxy grout you can get.

 

Edited October 30, 2020 by wozza

[MikeSharp01]

On 29/10/2020 at 19:40, nod said:

I always tell clients to allow 35  in total It’s easy to come up a little 

Sorry to poke an old thread.  So without the mat what would you tell clients? We have yet to choose our tiles we can self level up, we have 7mm to do already, if needs be. However we need to order the external doors and sliders and to meet part M I need to land within the 15mm allowance. Is a 10mm tile actually going to sit on 10mm of adhesive or does that get compressed somewhat when laid and if so by how much typically?

[nod]

Most tiles are 12-15 mil I would allow 

25-30 

As I said previously It’s easy to come up 5 mil or so

[MikeSharp01]

On 30/01/2022 at 21:40, nod said:

Most tiles are 12-15 mil I would allow 

25-30 

As I said previously It’s easy to come up 5 mil or so

Thanks. I will work the levels based on 28 and that will include between 3 and 8 mm of self levelling (3mm is just enough to cover the survey buttons in the slab and deal with a couple of low spots) and allow 15mm tile (just) I can self level once the windows / doors are in to fine tune against the, as yet, unknown tile thickness, I have not been told what we are having! Does that make sense? 

 

So the adhesive does not compress a lot, a 10mm notch results in a 10mm thick adhesive layer including back butter?