Decoupler Mat Required?

[Flip3seven]

Hi, I am currently looking at tiling an area of 43sq.m. 25sq.m is on screed with wet system UFH incorporated, which was laid three months ago. The remaining 18sq.m is on a combination of concrete slab and 70mm screed. The tiles are large format 600 x 600 porcelain
I am considering whether a decoupling mat should be used to avoid any problems with settlement in the future or if a S1 flexible adhesive would be sufficient on it's own.
What are your thoughts?

 

[GAZ5518]

Without a doubt I would use a decoupling mat.. no point in taking a chance when you can eliminate a possible problem at source.
GW.

 

[judge]

Agree with Gaz,also if both floor areas join you will need an expansion joint where they meet

 

[CJ]

Above replies spot on 👍

 

[Flip3seven]

Thanks for the advice. There is a step between the two floors, so no expansion joint required. Could anyone recommend a suitable decoupling mat and adhesive?

 

[Flip3seven]

Thinking about this further, would it be possible to use a S2 adhesive and eliminate the decoupling mat altogether?

 

[Kevbos]

Hi, I am currently looking at tiling an area of 43sq.m. 25sq.m is on screed with wet system UFH incorporated, which was laid three months ago. The remaining 18sq.m is on a combination of concrete slab and 70mm screed. The tiles are large format 600 x 600 porcelain
I am considering whether a decoupling mat should be used to avoid any problems with settlement in the future or if a S1 flexible adhesive would be sufficient on it's own.
What are your thoughts?

I would use a decoupling membrane ! Like durabase,!!

 

[eddcottee]

I wouldn't do it without a mat personally. Better safe than sorry