Hi @Mr Chibs. That's the waste pipe running from the utility room, which hasn't been used. Plus it's set back further than where the damp patches appear.
In the first photo is the best picture I've got. The back wall in that photo is where the units on the left hand side are in that gif...
Here's another shot of the UFH laid out in case it's helpful?
No leaks from above, this is a new extension after the builders removed the previous one and the ceiling is brand new... moisture is definitely coming from below. Only other pipe under the floor is the waste pipe (see first photo from my original post), but the kitchen and utility sink haven't...
Hi @dazlight
Screed was laid around 22nd November 2024
UFH was switched on 23rd December 2024 (last day that the builders were working as they took a few weeks off before returning towards the end of January 2025)
I've no idea whether a moisture test was done, however our builders have been...
Hi, we're currently reaching the final stretch of a home renovation. We've had wet underfloor heating put in on the ground floor which was left on for a couple of months at around 20 degrees. Below the UFH the builders put black sheeting and insulation before covering it all with a concrete...