Have I made a mistake..

Installed UFH in new extention (over block and beam) and Exisiting house (over new 100mm conc slab).

In the existing part I left in bits of old floor in two parts because new kitchen run is going over top and elsewhere because area covered by current kitchen units (we’re still living here)  which in time will become toilet&utility room so not bothered about UFH. Now covered with cemfloor 50mm liquid screed. 

To avoid heat loss from UFH screed slab I used 25mm PIR upstand insulation and the 8mm expansion foam right round. It was all busy busy and my head was fully down to get ready for liquid screed man window - miss it and it would have be 3weeks till next. 
 

Now everything’s dried I’m wondering if the 25mm+8mm is going to be ok to jump with the adhesive and decoupling mat below the tile. I’d be really interested to hear people thoughts 🤔😬

in most places the border between old and new will be 50mm under unit kick boards but in a couple of places it’s more out in the open of walkways. 
 

(Edit: the old terracotta coloured quarry tiles will be sds’d off and self levelled up to same high as screed, the decoupling mat (pictured) used to cover right through and tiled on top. 
 

TIA

Edited October 1, 20251 yr by EdSt
Edit needed