Best way to find invisible leak?

[Knappers]

Got a leak (I think) in a concrete floor.
No visible signs so trying to think of the best way to find it.
So far considered damp meter, UV dye, IR camera.
Any advice on the best way to locate it would be great 👍

 

[ShaunCorbs]

Depends how much you could get a gas system detector

 

[Gasmk1]

could you use air at pressure or the infra red camera

 

[gmartine]

Is it UFH? Can you isolate the pipework in anyway?

 

[WC1]

I don't know if this is genius or madness but I will try it next time I'm really stumped for the cause of the leak

 

[gmartine]

I read some of the comments... if you can't find the leak use FCUK it. Ha ha!!