Floor prep problems

[Lakey]

Hey guys

Was wondering if anyone could give me some advice re a floor tiling job I have coming up?
The area is approx. 20-25m2 and will be using 600x300 porcelains.
The floor is 2/3rds 20mm floorboards and 1/3 concrete as it is a kitchen and dining room that has had a dividing wall taken down to make one large room.
The timber floor area is between 5-10mm lower than the concrete floor and is generally quite uneven as is the concrete.
So do I Hardie the timber area then SLC the entire room or......?
Will I need an antifracture membrane at all?
Will I need a transition joint between the 2 substrates and as the tiles will be laid in a brick bond can the join be a Silicon join following the laying pattern?

Many thanks

 

[One Day]

I think I would fix 6mm wedi board to the timber floor (glue and screws). Then use a decent slc to level everything up.
Ditra (note I say "Ditra") the entire floor and tile away.

The "correct" way though would be as above, but fit a fixed expansion strip at the union of both floors.
Ditra either side of this, and then tile to it. It'll look ugly as hell though with 60x30s.

Using Ditra rather than just an antifracture membrane, I'd be happy enough with my first method as it's not a huge area.

 

[Dan]

If you use Mapei grout and Silicon the expansion joint the same colours as the grout (their silicones and grouts match perfectly) you'll hardly notice it.

If you can make the setting out fall so it's full tile either side the expansion joint, it's basically a grout joint.

Maybe a mm or two wider. Can't remember the regs with regards to expansion joint widths etc.

Schluter do some expansion strips. Might be worth getting them involved?

@Mapei UK Marketing @Schlüter-Systems Ltd - may be able to help.

Fair to say out resident large porcelain guru is @Ray TT @ Porcel-Thin

Although the tile size you're fitting are small compared to what he gets installed! Ha

 

[Spare Tool]

I think I would fix 6mm wedi board to the timber floor (glue and screws). Then use a decent slc to level everything up.
Ditra (note I say "Ditra") the entire floor and tile away.

The "correct" way though would be as above, but fit a fixed expansion strip at the union of both floors.
Ditra either side of this, and then tile to it. It'll look ugly as hell though with 60x30s.

Using Ditra rather than just an antifracture membrane, I'd be happy enough with my first method as it's not a huge area.

I once got hung out to dry for suggesting that on here..got told I need to go on a schluter coarse!! BUT back in the real world folk don't want to bugger up there nice brick bond kitchen floor with an expansion joint

 

[Rich Midge]

I once got hung out to dry for suggesting that on here..got told I need to go on a schluter coarse!! BUT back in the real world folk don't want to bugger up there nice brick bond kitchen floor with an expansion joint

Me too :-(

 

[One Day]

As will i probably for suggesting it now!
I'd sleep ok though.

 

[Lakey]

So insulation board, SLC and Ditra then?
I think I'll Silicon the brick bonded join then?!

 

[One Day]

So insulation board, SLC and Ditra then?
I think I'll Silicon the brick bonded join then?!

I'd only recommend this method with ditra. Not durabase or any other membrane. As for Silicon 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!

 

[One Day]

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

 

[Lakey]

So I guess ideally we need a join where the 2 different floors meet!

 

[Spare Tool]

I'd only recommend this method with ditra. Not durabase or any other membrane. As for Silicon 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 Silicon

 

[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 Silicon

I never advised the Silicon!

 

[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