Large floor

[One Day]

I did a 300sqm floor with royal mosa (quite expensive) onto heated anhydrite. Thankfully the customer saw the need to make sure it lasts so i got to do it properly. Otherwise, winging a job of that scale as a sole trader could see me lose my house!

 

[Italy]

because, do without DITRA is not correct ?.
I'm reading this trend, I laugh to keep from crying.
title of the trend says, sand-cement screed, UHF and tiles 100x50, thickness, I have not understood.
find a rule that says: DITRA obligation.or is it better with DITRA. (Say, only scluther).
take off my word pro, because I'm an outlaw.

 

[Just Rizzle]

always recommend decoupling then if client refuses your recommendation get a disclaimer signed by client before proceeding , cover your arse

 

[hmtiling]

on this forum is the only time i've heard a written disclaimer isn't legally binding. if it's not negligence then no case to answer. non use of a decoupler is not a factor that someone could be liable for floor failure! it's not even in BS!

 

[peteablard]

Tiling direct to a sand and cement screed with a porcelain tile isn't a problem. I'd do it all day long. If you know how to lay a tile properly you won't have a problem. There isn't a legal requirement to decouple so you can't be held liable if there is a problem. The issue is how well the screeding job has been done, you are trying to protect your work being affected by another persons. As I said before I recommend decoupling and explain why but fixing without isn't wrong. Natural stone would be different.

 

[J Sid]

that's the problem, the tradesmen we follow aren't what they used to be which means we have to use products and fixing method which in an ideal world shouldn't be needed.....

 

[One Day]

Stop moaning.

'tiler'll sort it'

 

[Dumbo]

even if the screed has been done well it's the underfloor heating that is going to cause the problems with the heating and cooling cycles and expansion and contraction of the screed

 

[Dumbo]

I did a 300sqm floor with royal mosa (quite expensive) onto heated anhydrite. Thankfully the customer saw the need to make sure it lasts so i got to do it properly. Otherwise, winging a job of that scale as a sole trader could see me lose my house!

Jcr tiling llp

 

[J Sid]

even if the screed has been done well it's the underfloor heating that is going to cause the problems with the heating and cooling cycles and expansion and contraction of the screed

its not the heating and cooling cycle in its self that's the problem, its the cracks it courses in a bad laid screed.

 

[Dumbo]

its not the heating and cooling cycle in its self that's the problem, its the cracks it courses in a bad laid screed.

As I said expansion and contraction . Cement with additives and fibres it's going to crack over that sort of area .

 

[J Sid]

it shouldn't crack all over the place. It shouldn't crack at all, if it does, its failed.

I've had tiles crack on a few occasions even with an uncoupling membrane, they aren't a cure all product.

 

[One Day]

I've never had any crack on Ditra - ever.
I've seen L cut tiles crack on ditra, but that's due to the stresses in the tile - not the floor.
As far as lateral movement I honestly believe Ditra (not others) to be as good a guarantee against cracks as you'll ever get - short of incorporating an old-fashioned sand layer into the floor.

 

[Dumbo]

So whenever a floor fails we just point the finger at the screeders .

 

[J Sid]

I've never had any crack on Ditra - ever.
I've seen L cut tiles crack on ditra, but that's due to the stresses in the tile - not the floor.
As far as lateral movement I honestly believe Ditra (not others) to be as good a guarantee against cracks as you'll ever get - short of incorporating an old-fashioned sand layer into the floor.

yes they were L cuts, but on removing tile and Ditra the screed had cracked in the same place as tile.