When Do You Uncouple?

[Flintstone]

I have used uncoupling mats before, but not extensively. It's only maybe the last 18 month or 2 years that my local tile shop has stocked them.

When do you personally use an uncoupling mat and when don't you? Materials and substrate.. I understand what lateral movement is, but I have seen people using mats on solid floors I think

 

[Callum Curwood]

I normally go with it when the floor transitions between two different substrates or if I've got a good few door ways to pass between as it relives the stress which doorways do to remove the chance of cracking in the future. Normally if I'm just on 1 substrate the I prep that as needs be

 

[One Day]

I don't always use them. Heated floor of a large size, yes. Small heated floor, not unless I'm fixing some weak stone. Fresh screed, yes. Anhydrite screed, always (at least until I'm convinced by gypsum adhesive). Typical thought process is highlighted by a job I'm soon taking on... 300sqm of high quality porcelain onto heated anhydrite screed. In theory i can tile direct using gypsum adhesive. Will i risk 15k worth of tiles popping? No way. Its ditra for me.

 

[Dhtiling]

Wood subfloor or lots of windows. Almost all my floors are over wood, so basically every job I do. Things move at different rates and it seems like cheap insurance. An added benifit is most membranes are lighter and easier to work with than hardi.

 

[hmtiling]

large pumped(gypsum) heated floors definitely

 

[Flintstone]

Wood subfloor or lots of windows. Almost all my floors are over wood, so basically every job I do. Things move at different rates and it seems like cheap insurance. An added benifit is most membranes are lighter and easier to work with than hardi.

This is one thing I don't get, what's wrong with over boarding with hardie or no more ply. It's solid and there is not gonna be any lateral movement. Why use a membrane instead ?

 

[Stef]

I only decouple when I'm using stone.
I see someone has stated that they use it to go between 2 different substrates.
That's not what Ditra is designed for, there should be an expansion join in the tile face following through from the substrate.
Also through doors you should have a break in the tile between joining rooms.

 

[J Sid]

I've been using Ditra for about 15 years now.
When do I use it.... over all wet ufh, under all stone, over all wood and over green screeds.

 

[Flintstone]

Over all wood, would you use it on a 4m bathroom floor. Floorboard, hardie, then 300x300 porcelain ?

 

[Stef]

Over all wood, would you use it on a 4m bathroom floor. Floorboard, hardie, then 300x300 porcelain ?

I wouldn't as I see that as over kill tbh.
If you look at the American market almost everyone over there uses a decoupler on every substrate.

 

[J Sid]

Over all wood, would you use it on a 4m bathroom floor. Floorboard, hardie, then 300x300 porcelain ?

If floor boards are solid then I would Ditra, even a 1m2 floor, if not so solid then I would HB it

 

[Flintstone]

I still don't see the benefit of it instead of boarding

 

[J Sid]

A lot quicker to prep the floor than HB if sub floor is solid

 

[MW Smith Ceramics]

Personally I would never ditra onto floorboards as this won't stabilise the floor, even if it is solid it's too many separated peices of wood for me, I've always over boarded with Hardi backer or no more ply 6mm or 9mm if possible glued with polyurethane adhesive and screwed......bombproof

 

[MW Smith Ceramics]

I don't always use them. Heated floor of a large size, yes. Small heated floor, not unless I'm fixing some weak stone. Fresh screed, yes. Anhydrite screed, always (at least until I'm convinced by gypsum adhesive). Typical thought process is highlighted by a job I'm soon taking on... 300sqm of high quality porcelain onto heated anhydrite screed. In theory i can tile direct using gypsum adhesive. Will i risk 15k worth of tiles popping? No way. Its ditra for me.

That gypsum based adhesive scares me too impish!.....don't mind laying the decoupling membrane with it ( Bal rapid mat mostly ) then flexi cement based addy