200sqm floor, prep discussion

[Benn Simmonds]

Thanks. Is a decoupler required? We use them with natural stone but from researching am led to believe with porcelain and a flow screed it isn't necessary.....?

It' not really necessary but it' belt and braces. If you think you should use it then do. It will cost you more if the floor fails.
Personally I would Matt it and tile it.

 

[Dumbo]

If you look at the difference in expansion between porcelain and anhydrate there is a difference. Not sure what it is but their is and over a large area it matters because it adds up . So I would very much decouple

 

[Chris Gibbs]

Thanks. Is a decoupler required? We use them with natural stone but from researching am led to believe with porcelain and a flow screed it isn't necessary.....?

I would use an anti fracture mat. Anhydrite floor isn't prone to big movement but when heating goes on underneath you cant be too careful. it also gives the customer confidence in your methods too knowing you're covering all bases.

 

[Chris Gibbs]

on an Anhydrite floor

 

[Dumbo]

I would use an anti fracture mat. Anhydrite floor isn't prone to big movement but when heating goes on underneath you cant be too careful. it also gives the customer confidence in your methods too knowing you're covering all bases.

I believe from figures quoted by @Ajax123 on a previous thread unless I misunderstood that the porcelain expands more than the anhydrate

 

[Chris Gibbs]

I believe from figures quoted by @Ajax123 on a previous thread unless I misunderstood that the porcelain expands more than the anhydrate

exactly... and these floors can get quite hot if required

 

[Chris Gibbs]

I believe from figures quoted by @Ajax123 on a previous thread unless I misunderstood that the porcelain expands more than the anhydrate

exactly... and these floors can get quite hot if required

 

[GoneGuy]

I would go belt and braces and use a anti fracture mat.

 

[Flintstone]

I wouldn’t and I don’t decouple on anhydrite with porcelain and ufh.

A new sand and cement screed with ufh - yes

 

[Alex Reed]

Thats great. Thanks guys. Will see the builder/owner this week and suggest all possibilities to him. We done a 150m2 porcelain one before Xmas with Ditra but that was on sand/cement screed. Have been using BAL rapid Matt on the last few floors (40 m2 plus) onto nu heat gypsum boards with wet ufh screwed down to glued and screwed caberdeck stuck with mapei S2 and then tiled with Weber s1. Floors seemed really solid. Time will tell....... Thanks for your knowledge guys