anti crack matting (detra etc)

[tile anorak]

Hi guys
I have a floor lets say 40sqm and one corner is floor boards (say 10sqm), the rest is concrete. Basically the customer has opened up a few rooms into one big one. I Believe I have to use detra matting (obviously on timber floor) in whole room as it's going from one substrate to another.
Is this correct or is there another way around this?
If I do have to do the whole floor it's an expensive job so the sake of a quarter of the floor.

 

[Stef]

I've heard Ditra called "Magic Mat" & it would have to be if your going to use it like this.
You really should have an expansion gap between two substrates.
You could be lucky & it could last for years or it could fail in a few months..

 

[tile anorak]

i thought thats what anticrack matting is for???
:shocked3:

 

[Ajax123]

Oh dear.... Back to school....

im not a tiler so here is my take.... Either take up the floor boards and reinstate with something more suitable e.g. 18mm ply after ensuring the joists underneath are sound and free from deflection which probably means installing noggins, then over boarded with 6mm hardibacker. If the concrete floor is then slightly lower use SLC to bring it back to flush.

Add ditra if still needed... I probably would personally...

Then prime and tile as normal ensuring there is a movement joint in the tile face at the interface between substrate types.

You are a tiler.... What are your thoughts...

 

[TJ Smiler]

Wouldn't use the Ditra on the wood (Ditra or any equivalent is for lateral movement and wont provide much benefit on a floor that has bounce and it wont work in place of an expansion joint) as Steff says, you may be lucky but why take the risk.

Take up the floor boards and add noggins at every 300mm then screw down 22mm wpb ply (there are other materials/ways you can do this part depending on your budget). Prime, then tile using an expansion joint. This is a basic guide and each job will vary, but without seeing it this is the type of prep you wanna be looking at.

Is possible that you could screw down the floor boards and then overboard but it depends on height restrictions, strength, bounce etc.