Floor prep problems

[Spare Tool]

I'd only recommend this method with ditra. Not durabase or any other membrane. As for silicone on the joints, it won't hurt, but i wouldn't bother.
As i explained firstly, this isn't the 'correct' way, so it's your risk!

Don't try and back out of it now

Your main risk in my opinion is if the floors rise or fall at the join. Ditra won't save you then!

Neither will silicone

 

[macten]

I did 90m2 multiroom using this method. Was a modular pattern and I added joints at doorways and an extra one in the largest room. No way could you follow the timber/concrete transition as it was totally irregular rather than a straight line.
5 years on and it's still mint.
You always worry when you don't do it by the book though.

 

[Lakey]

I did 90m2 multiroom using this method. Was a modular pattern and I added joints at doorways and an extra one in the largest room. No way could you follow the timber/concrete transition as it was totally irregular rather than a straight line.
5 years on and it's still mint.
You always worry when you don't do it by the book though.

How did you join in the large room?

 

[One Day]

Don't try and back out of it now

im not!
Neither will silicone

I never advised the silicone!

 

[Flintstone]

I have done a very similar thing this week, I'm grouting up as we speak, a stud wall has been removed and left floor boards in one half and concrete in the other. I boarded over the floor boards with no more ply which brought the level perfect, then tiled it all. I did advise an expansion joint but they didn't want one of course. I made sure they are all solid bedded and there was no deflection

 

[Flintstone]

 

[Rich Midge]

My method is slightly different. I carry the backerboards over the transition, glued and screwed into the solid floor and the timber. SLC the solid up to the height of the backerboards then decouple over the lot.

 

[Flintstone]

My method is slightly different. I carry the backerboards over the transition, glued and screwed into the solid floor and the timber. SLC the solid up to the height of the backerboards then decouple over the lot.

That's basically what I did but no un coupling.
I once did one and just uncoupled the joint, about 1m wide

 

[Mapei UK Marketing]

Hi all,

Hopefully this is in time for the project mentioned if not hopefully it will be good reference for future projects. Our Technical Services Team recommend the following...

Overlay the floorboards with an appropriate board system such as minimum 15mm exterior grade plywood screwed at a maximum of 300mm centres or tile backer boards. We would advise speaking to the board manufacturer to ensure a suitable system is used.

When tiling in an area that consists of different substrates, such as timber & concrete, a movement joint must be mirrored through to the tiled finish. This will allow for any stresses and or potential movement which can occur between the different substrates. To infill the joint we would suggest using Mapei Mapesil AC for ceramic or porcelain and Mapei Mapesil LM for natural stone.

If you require further assistance please contact Mapei Technical on 0121 508 6970. Option 2.

Hope that helps!