Tiling over "composite"

[garfield59]

Hi,

We live in an ex-council semi and some of the original floors were finished with a brown, smooth material (careful) that my wife reckons was always called "composite". Apparently it used to be just polished but covered with carpets if you could afford them. The surface is hard but when you break it you find a thin brown skin about 3mm thick over a darker ash like substance which breaks up easily and if you heat it up, or just hit it you get a smell like gas. The first time I had to drill some fixing holes through it I thought I'd hit a gas pipe but it was just this flooring getting hot around the drill bit!

Anyway, several years ago we had "Rhinofloor" cushion floor professionally laid throughout the kitchen, utility room and hall but after a few months we noticed yellow stains on the flooring, but only where it was laid over composite; on concrete substrate the finish was fine, there was no discolouration. We had the flooring supplier come out and he took a sample from under a kitchen unit and sent it away for analysis. Turns out the glue for holding down the flooring was reacting with the composite and making a yellow stain on the top surface of the flooring.:furious3:

:yawn:Thanks for your patience so far but the point of my rambling is, do you think I could replace the Rhinofloor in the kitchen with tiles and what would I need to do to stop the composite affecting the tiles or grout? Someone out there must have tiled over this stuff before?

Thanks again for your patience and I know the answer will be out there....

Garfield

 

[PHG Dave]

Sounds like a bitumen type material, I would guess that the solvent in the glue used to stick down your vinyl softened what is an oil based material.
If at all possible i would recommend removing all of this coating before tiling.

If not possible I think there are specialist primers out there that will seal it off and allow you to tile on top as long as it is solid - anyone from Mapei want to comment?

 

[garfield59]

Well it's two years ago tomorrow that PHG Dave replied to my original question and I haven't done the kitchen floor yet! Plenty of other things have been done but now it looks like the kitchen will be next springs project.
I haven't had any comments from Mapei so I've looked at other posts on here and at least two primers have been mentioned i.e. PCI 303 and SBR. Since things have probably moved on in the tiling world in two years can anyone suggest which primer would be best on this composite material? Otherwise, should I put a layer of self-levelling compound down and then tile onto that after a suitable delay?
By the way, it's good to be back!
Garfield

 

[Dougs Third Go]

I thought I'd replied to your original post, (but could 've been one similar I suppose) it sounds like a reaction and leeching. Apart from taking up the bitumen I'd suggest putting a slurry coat of sbr/cement over the bitumen, then even a decoupler as ditra (not for decoupling, but as a vapour/moisture barrier, that should certainly stop any ingress and staining from the blackstuff.

 

[garfield59]

I like the idea of using a barrier between the old and the new. Can I show my DIY ignorance by asking what kind of mix would be needed for the sbr/cement slurry coat? I can then add the material to the list of stuff I need to buy before the spring.
Thanks again Doug