First problem in 10 years....

[Bill]

Ok so I've removed the tiles to find dark patches and water literally running off the underside of the tile. I'm presuming this can only indicate too much moisture in the screed......

Are you sure the heating pipes aren't leaking?

 

[LM]

Sounds like too much moisture in the screed then. The Ufh may have been pressure tested but it doesn't sound like it's been commissioned.

 

[Flintstone]

sounds like the screed was no where near dry!
Have you confirmed it's not anhydrite as well?

 

[Danj]

Definitely concrete, when I say dark patches.....it's not wet just darker shades of grey. I'm convinced it was too green

 

[Flintstone]

If it's soaking wet under the tiles all over, the screed wasn't dry simple as that!

 

[hmtiling]

i'd be surprised if it's anything other than a wet screed.

Ahem

 

[Danj]

Yeah it's looking that way, I just wanted to put it out there see if there was anything else that could cause it as I do have a good relationship with the builder. Now I just need to find an extra 4 days.......as normal.......

 

[Danj]

Thanks again for all the replies, this is the first time I've ever done this......great experience

 

[Danj]

Time to buy a moisture meter.....any advice?

 

[spooner68]

I've always put the guidelines for drying times and how to commission UFH into my quote so its in black and white. As the years have gone by this has become a standard (lengthy) paragraph but on the 2 occasions there have been problems I've found that either the screed hadn't been left to dry long enough or the UFH had just been cranked up to 11 from the off.
I always get the client to put a piece of polythene down under a brick/tin of paint/tile overnight to do a rule of thumb check. Have had to postpone a few times as it was still wet mind!
There's a lot said about decouplers but I have never seen the need on a concrete screed. Thoughts?