Floor bricks, pamments and underfloor heating

[ian]

Are you just mopping wet with clean water? You could try a very very weak water with viakal (descaler) mix on a well wrung out mop. A few drops per bucket may do the trick and disolve what may be a lime film on the tiles. If the mop is fairly well wrung out, the solution should not seep too far into the gaps. Otherwise wait patiently for the lime to carbonate a bit more and try this then.

 

[AMc]

It's a good thought - I have been using clean water so far with the intention to try and let the stuff in the gaps harden as much as possible before I start in with chemicals. I'll look at applying something mildly acidic if it doesn't get better soon.
At the moment I have the adjoining kitchen to joint, knowing how messy this will be I can't be too fussy about the vinery until then - but any suggestions are welcome for when we're ready, thanks!