Unsure how to fix tiles to this substrate

[highlandtiler]

Hi All
I am trying to fix some broken tiles in a couple of wet rooms in a customers house. When I took up the first few tiles they seem to be on some kind of rubber/ bitumen elastic membrane which I have never seen before. Have any of you seen this before and how should I go about fixing the new tiles? I have attached a couple of photos.
This membrane has been fitted directly to the chipboard and the tiles were loose. Some others have cracked as predicted as they were fixed directly to chipboard! Unbelieveably the customer has 6 bathrooms all tiled the same way and the hall is also tiled directly onto chipboard! The customer knows that the new tiles will crack as well eventually but just needs a serviceable short term solution.
I would be very grateful for your views. Thanks in advance!

 

[Dan]

The chipboard needs to come up and be replaced with ply and ditra.

Or perhaps ply and aqua panel or something.

That needs to go in bin though that.

 

[highlandtiler]

Problem is though that the chipboard IS the floor. there is no ply , ditra uncoupling or anything ! Any idea what the black stuff is?

 

[p4ulo]

Doesn't look like it goes underneath the wall tiles, so its not properly "tanked" for a wetroom.
Sheesh, looks like a right pickle.

 

[highlandtiler]

Your absolutely right P4ulo and all the wetrooms are the same. I think the black rubbery stuff is an attempt to keep the chipboard dry ! The worst thing is that it has underfloor heating as well so eventually they will have major problems.

 

[p4ulo]

Oh Jeez!!! Sounds like its gonna have to all come out to do a proper job mate, at least the floor and 3 courses of wall tiles to put down a proper tanking??

 

[Ian]

That membrane looks like impey tile safe, could be wrong but it has the mesh in between two layers of bitumen.

 

[highlandtiler]

I would agree - the only problem is that he has 4 wetrooms so big bucks - but maybe nice for me!

In the meantime though how can i fix tiles to that black stuff? Flexible adhesive like rapid set ?

 

[Dan]

We concentrate a bit too much on what it is. When the solution is the same.

If you want to tile in there, that needs to come out and you want to ply it, waterproof it, and tile it.

Doesn't matter too much what it is now its destroyed.

 

[AliGage]

The black stuff is a cement based waterproofing coat. Such as ardex WPC.

Unfortunately there is no shirt term solution. If the waterproofing is compromised then it's gonna leak.
Certainly if it's on chipboard too.

If your client isn't looking to redo the wetroom then the only solution other than a rip out is to install a shower tray in the area. One with is on legs, breakout the floor to extend the waste.
Still bot a small job, but that wetarea if not sorted properly will force them to rip out sooner than they'd of hoped for.