Fixing ceramic floor tiles

[F]

Currently removing old 'lino' tiles from a concrete floor. They are to be replaced by ceramic floor tiles for which I've got the appropriate 'ceramic floor tiles to concrete floor' adhesive.

Some of the tiles are quite loose but most are resisting. However, when they do finally lift there's the remnants of black adhesive left on the concrete which has a petroleum type smell.

Question is, does it have to be removed before the new adhesive will stick? If it does, does it have to be completely removed and what will remove it?

TIA

[Andy]

Have tiled over similar before without any problems, the black residue is probably a bitumen adhesive. You don't need to remove it all but if you do want to, you could try white spirit.

You mentioned you have purchased 'ceramic floor tiles to concrete floor' adhesive, sounds to me like the B&Q tub stuff. I would recommend you take it back and get some power adhesive (BAL) from somewhere like Topps Tiles, its far better in the long run than the ready mixed stuff.

Andy

[The Natural Philosopher]

Also look for Ardurit (Ardex) compounds.

Their rapid set is pretty useful over concrete,. Ain't cheap, but it sticks like a bugger..

[John]

I'm doing the same job. Petrol seems the best solvent. Don't smoke and have plenty of ventilation, especially in this hot weather.

John

[HLAH]

"The Natural Philosopher" wrote

I'm sure I read somewhere Bal and Ardex are brands owned by the same parent company. Don't know if it's true or not.

H

[F]

Thanks. It seems to be 'going off' gradually. Less soft, less smelly.

Unibond. Is it really that bad?

[The Natural Philosopher]

Not good for floors.

[F]

In what sense? It says it's for sticking tiles to concrete floors so I'm interested as I don't want to have to repeat the work.

[The Natural Philosopher]

Brittle, low grip and not very waterproof is my impression of the Unibond tile cements I have used in the past. Fast though, for walls especially the white tile'n'grout ones.

The stuff you have to mix yourself can set far more aggressively than premixed..The Ardex rapid set is tougher than the concrete its stuck to..

[Andy]

I would agree with the above 100%. Although I haven't personally used Ardex products, I think I'm correct in saying that power based adhesive are cement based thus giving their extra strength.

Although its very convenient to buy the adhesive in a tub, in the long term it may fail. Mixing the powered stuff is really easy and only takes a few minutes.

Andy