Uncoupling membrane

[jimbo]

I have a floor area approx. 30m to tile. Half is on exterior ply the other half on screed. Will I need to put down a uncoupling membrane over the whole area before I tile. The tiles are ceramic .

 

[jimbo]

Forgot to mention the floor will have underfloor heating

 

[Daz]

In principle, you do not require a decoupling membrane. You will just need to ensure that you have an expansion joint across the point where the two substrates meet.

However, things to consider are:
How stable is the ply floor? i.e. thickness, deflection etc..
Are you putting insulation boards under the UFH? (I presume it is electric UFH)
Do you intend to apply a floor smoothing compound over the UFH?

 

[White Room]

You will need a control joint between the screed and ply floor, what thickness of ply is fitted

 

[The Legend; Phil Hobson RIP]

Hi Jimbo, what thickness is the ply? decoupling also expansion joints to be considered Thickness of ply important, before we can advise

 

[The Legend; Phil Hobson RIP]

Triple response, same answer

 

[The Legend; Phil Hobson RIP]

Bet that is not a record though, knowing this forum

 

[Yorkshire Tiling Services]

Same

 

[jimbo]

Thanks for the quick response.It is 18mm ply and a wet piped system layed on insulation board. How can I disguise the expansion joint without it looking obvious

 

[Ajax123]

whilst it will do no harm I would not have thought uncoupling essential with ceramic but the joint is essential.