half wood half concrete....

[fizz_bosh]

Hi All,

You have been really helpful before when it came to tiling my bathroom with limestone (I had a nightmare tiler who didn't seal the tiles, i ended up re-honing each one to get rid of stains !!)

.. now its time for the kitchen & I have 18sqm half timber joists/T&G and half is 5month old screed (70mm) on top of 70mm celotex on top of concrete block and beam floor (part of new extension).

The main thing is that I don't want a visible expansion gap on the finished floor. Can I avoid this by using Ditra matting over the whole area?

I was thinking of using a tile backer board over whole area, stuck down with adhesive & screwed on the timber half. Then ditra, then tiles... hoping no joint it necessary?

Can this work?

If not, other suggestions/advice is very welcome..

Thanks

 

[afright]

Hi,I had a problem laying limestone in the same situation the customer did not want to see an expansion joint but it did crack and he agreed that he had have one try this Schluter profile

 

[DHTiling]

What screed type is it.?

 

[fizz_bosh]

Hi, thx afright for the comments & pic. I have decided not have the floor tiled if an expansion joint is essential as I don't want the visual delineation of old house & extension half way thru' the kitchen.

David - The screed was a standard cement mix with fibres. Depth is 70mm. Not sure I know anything else about it :-/

Has anyone had 'successful' experience tiling in this kind of situation WITHOUT a movement joint?

 

[DHTiling]

You could install what is called a cold joint at the 2 substrates intersection. this would need to be min 5mm wide depending on the length of the 2 substates.. this is filled with a matching silicone to the grout colour..

This will then be a lot less noticeable than a preformed 10mm metal/plastic strip joint.

Starting a full tile either side of the substrate split would look less obtrusive.