Ditra membrane confusion - Tile Advice

[Jim508]

Afternoon all,

I'm currently in the middle of renovating my bathroom and I'm close to tiling the floor. I've only ever tiled a floor once and that was just onto a self leveling compound. Considering it's upstairs I've fixed a plywood subfloor down for added strength and flatness but I'm very confused about the adhesive for the ditra matting and tiling adhesive. The only advice I can find mentions modified mortar but is that the same as UK mortar? I've got two bags of S2 ultraflexible adhesive, would it be OK to use this under the membrane and also on top? Also, would it be a good idea to seal the plywood with SBR before I lay the membrane?

Many thanks,
Jim

 

[hmtiling]

Ply isn't the best choice here and to be honest neither is ditra. You could use the s2 to fix the ditra down but it isn't recommended on top of it. I'd overboard the ply with a 6mm cement board and tile to that with the s2

 

[Steve6690]

Have you overboarded an existing floor with the ply?

 

[Jim508]

Have you overboarded an existing floor with the ply?

Yes I've overboarded the orginal floorboards with plywood to add strength and purhaps create less flex in the floor?

 

[hmtiling]

Are you just waiting for the answer you want?

 

[Jim508]

Are you just waiting for the answer you want?

Definitely not, as I said I've never tiled on a wooden floor so I thought best to ask people who know what they're talking about. I watched a few videos online and I only ever saw people use plywood on top of floorboards so I'm unsure what your response was. Would you suggest ripping up the plywood and using the cement board as you suggested?

 

[hmtiling]

Definitely not, as I said I've never tiled on a wooden floor so I thought best to ask people who know what they're talking about. I watched a few videos online and I only ever saw people use plywood on top of floorboards so I'm unsure what your response was. Would you suggest ripping up the plywood and using the cement board as you suggested?

Sorry. No, leave the ply and use a 6mm cement board instead of the ditra. You'll be 2mm higher than with the ditra. If that's too high remove the ply and just use 6mm cement boards.

 

[Jim508]

Sorry. No, leave the ply and use a 6mm cement board instead of the ditra. You'll be 2mm higher than with the ditra. If that's too high remove the ply and just use 6mm cement boards.

Will do, cheers bud.

 

[hmtiling]

Will do, cheers bud.

Good luck

 

[Tony_C]

As Harry has mentioned, I'd have left the ply out the equation and went straight to backer board over the floor boards providing there wasn't much movement

 

[Time's Ran Out]

Now I would have done the same as the OP!
Strengthened the floorboards with plywood and covered with ditra for an uncoupling membrane and fully waterproofed subfloor.

 

[hmtiling]

Now I would have done the same as the OP!
Strengthened the floorboards with plywood and covered with ditra for an uncoupling membrane and fully waterproofed subfloor.

so you would have taped the seams with kerdi koll and and banded up the walls too?

 

[Time's Ran Out]

so you would have taped the seams with kerdi koll and and banded up the walls too?

As it’s a bathroom yes!
Fully waterproofed.

 

[hmtiling]

As it’s a bathroom yes!
Fully waterproofed.

I don't believe you!

 

[Jcshutts]

Not sure why the ditra isn’t a good add. I agree the cement board is far better than ply. If it’s an option I would remove the floorboards and place a 22mm cement board down and then ditra and tile. Thoughts?