Different substrates in one job

[rj1884]

Hello. Went to look at a job yesterday where the customer wants a downstairs utility room, entrance hall and living area tiled using porcelain tiles following the flooding of the whole area. The substrate in the utility room is currently green chipboard. The utility room runs into a large entrance hall area which is concrete screed which has been down for many years. The screed will be prepared and levelled appropriately by the customer. My question is relating to the expansion joint from the utility to the entrance hall. Would you guys remove the chipboard and replace with ply. I was thinking of overboarding the chipboard then tile straight to that and the screed with the porcelain tiles. If the screed is sound would you ditra the whole area or go straight to the screed. If no ditra is used would it be a case of putting in an expansion joint where the substrates meet or do you have to use ditra as well.
My plan is to get the screed brought up to the level of the utility room floor if possible.

Thanks in advance.

 

[Qwerty]

I would ply, Ditra the lot and incorporate expansion joints where required. Remember this needs to be from top of tile surface right through to substrate when the two different types meet.

Have a read of this recent thread.... http://www.tilersforums.com/43-tiling-forum/73705-large-floor-advice-expansion-joints-needed.html

 

[White Room]

Hello. Went to look at a job yesterday where the customer wants a downstairs utility room, entrance hall and living area tiled using porcelain tiles following the flooding of the whole area. The substrate in the utility room is currently green chipboard. The utility room runs into a large entrance hall area which is concrete screed which has been down for many years. The screed will be prepared and levelled appropriately by the customer. My question is relating to the expansion joint from the utility to the entrance hall. Would you guys remove the chipboard and replace with ply. I was thinking of overboarding the chipboard then tile straight to that and the screed with the porcelain tiles. If the screed is sound would you ditra the whole area or go straight to the screed. If no ditra is used would it be a case of putting in an expansion joint where the substrates meet or do you have to use ditra as well.
My plan is to get the screed brought up to the level of the utility room floor if possible.

Thanks in advance.

That worries me....

 

[AliGage]

Is there a difference in levels at present?
I take it the chipboard is new due to previous substrate being Fubar'd in thw flood?

 

[rj1884]

Hi. The floor is being prepared by a flooring guy who lays wooden flooring. Yes it's new due to the flood and at present the floors are different levels.

 

[AliGage]

How do they differ?

 

[rj1884]

To be honest it's not a great difference. It'll have to be raised about 10-15mm once the chipboard has been over boarded.