De-Coupling membrane would you insist

[DHTiling]

2 threads you might get some info from...

http://www.tilersforums.com/tiling-forum/14730-understanding-tiling-shift.html


http://www.tilersforums.com/tile-ad...nt-joints-expansion-joints-control-joint.html

 

[Ajax123]

Does anyone know where i can down load a picture of this???


Many thanks for everyones replies....[/quote]

Not sure if this helps but this is a sand cement screed that did not have the UFH comissioned prior to floor covering being placed. If this happens under your tiles bang they go. If Ditra used the tiules are separate from the screed so reduce the risk very significantly. Not sure if I uploaded it right cos not a computer whiz - I know about screeds though....

 

[White Room]

That screed dos'nt look deep enough, the pipes are visible

 

[Ajax123]

That screed dos'nt look deep enough, the pipes are visible

Pipes visible cos big hole in screed ... rrr:

seriously though the pic is a bit deceptive - was actually 40mm cover to the pipes which should be enough - 65mm overall depth reinforced class B screed.
Is quite an old pic - probably 10 years plus now. We repaired this one with an Epoxy resin after filling in the holes. (there were several failure sites like this one. Failure was due to thermal shock though. Vynil flooring was laid with primer and leveller (removed prior to pic) and then the heating was switched on at relatively high temp. Screed cracked - flooring failed. IMO if Ditra had been used and tile laid over the top then tiles separate from screed so screed movement not a major issue.

 

[White Room]

Ditra would have kept some moisture there.

 

[Ajax123]

Ditra would have kept some moisture there.

It would also have acted as a vapour stbilisation layer allowing the screed to continue drying allbeit very slowly. The moisture would not have been disruptive to the tiles cos they would be separate. As it happens in this case I don't know if the screed was still damp or not.

 

[LM Ceramics]

me personally depends on the tile being fixed if it is ceramics i would use a flexible adhesive grout etc but id place an expansion joint round the perimetre of the room

if using natural stone trav or limestone i would insist on using an un coupling membrane