Will this need a uncoupling mat

[poynton phil]

41 msq Porcelain, over water fed in screed ufh, I told the customer it will need a uncoupling mat, but they have asked me to go ahead without it, will it be ok, or should I refuse the job. Any advice will be appreciated.

 

[Ajax123]

Wouldn't normally expect uncoupling with porcelaine provided the screed is ok. I.e. Minimum 65mm with fibres or mesh. Also Check for joints in the screed at door thresholds and between zones and typical maximum baby's of 15to 20m2. If it is cracked at all uncouple regardless.

 

[poynton phil]

Would this need expansion joints

 

[AliGage]

Whats the dimesions of the room?

 

[poynton phil]

Its a area of 6.4mx4.25m, with another area of 2.7mx3.8m joining it

 

[AliGage]

Is there an expansion joint where the two join then?

 

[poynton phil]

Its 2 rooms that have been opened up to make one, there is no expansion joints in the screed, between the 2 areas.

 

[AliGage]

So your longest run is 9.1? Then yes.
For the life of me the square meterage evades me. Couldn't guarantee a guess. But pretty sure its a max of 8m in one length before one is required.