Expansion Joints

[m3fitter]

Found this on schluter website: Successful installation over floor heating systems using an uncoupling membrane - Schluter-Systems


Precaution should be taken when installing ceramic tile and natural stone over heated substrates. The effect of temperature fluctuations during the heating and cooling processes induces thermal movement that without proper compensations will lead to failure in the surface covering. Applying an uncoupling membrane has proven to be a successful technique for a variety of floor heating systems
An uncoupling membrane serves several functions in successful tile installations and is particularly suitable for floor heating systems.
The membrane uncouples the tile covering from the substrate and prevents the transfer of stresses to the tile flooring. As a result, stresses caused by deformation of the substrate through thermal movement, shrinkage of the curing screed or concrete, deflection, etc. are neutralized.

 

[Ajax123]

Found this on schluter website: Successful installation over floor heating systems using an uncoupling membrane - Schluter-Systems


Precaution should be taken when installing ceramic tile and natural stone over heated substrates. The effect of temperature fluctuations during the heating and cooling processes induces thermal movement that without proper compensations will lead to failure in the surface covering. Applying an uncoupling membrane has proven to be a successful technique for a variety of floor heating systems
An uncoupling membrane serves several functions in successful tile installations and is particularly suitable for floor heating systems.
The membrane uncouples the tile covering from the substrate and prevents the transfer of stresses to the tile flooring. As a result, stresses caused by deformation of the substrate through thermal movement, shrinkage of the curing screed or concrete, deflection, etc. are neutralized.

but
suchluter don't write the standards, they sell ditra. Not saying it is not of benefit. Clearly it can be but as per my pm it is not always necessary.

 

[Ajax123]

No reason for it to be private so have put it in the public thread hope that's ok with you m3fitter

q. Are you saying that Ditra isn't recommended on screed with UFH ???



A. not in all cases. The British standard only make reference to the need for uncoupling natural stone tiles. This recomendation is reflected by the British stone federation. Even then neither say that uncoupling should be by means of an uncoupling membrane such as ditra. Uncoupling can be achieved by other means. Realistically the ditra type systems are the modern way to acheive uncoupling.


The success or failure of any floor also depends on the quality of the substrate. If the screed is laid correctly and the tiles are laid correctly with appropriate joints etc etc, then it is arguable and indeed likely that uncoupling would not be needed with any tile type, except the natural stone caveat.


all that said if you can get the dosh for it then it is not likely to do any harm so go for it...

 

[m3fitter]

of course, I understand, but as a tiler, trying to alleviate problems and keep a good relationship with developers that use you year in, year out, I have to advise them of the fact that decoupling, can only benefit them, especially on large areas, if the screed hasn't been installed with movement joints

 

[Ajax123]

of course, I understand, but as a tiler, trying to alleviate problems and keep a good relationship with developers that use you year in, year out, I have to advise them of the fact that decoupling, can only benefit them, especially on large areas, if the screed hasn't been installed with movement joints

Ill agree with that. Seems sensible.

 

[AD Ceramics]

Ill agree with that. Seems sensible.

Phew........ that was close, I thought it was gonna kick off.

Thanks all for the replies.

Regards

Paul:sofahide: