Re-Using Wall Tiles

[richlist]

I have a question for all you tiling experts out there......

I had a small area of wall tiling that had come way from the wall. The tiles hadnt fallen off they had just come away and were loose. I have managed to carefully remove them all (without breaking any) so that all the tiles left are firmly attached to the wall. I've soaked the tiles in water and scraped off the old tile cement and am letting them dry out. I've also scraped the old tile cement from the wall (plaster board). The area to be re tiled is about 0.5 sq metre.

I have some Unibond ready mixed tile adhesive & grout.

Most of the adhesives I looked at tell me that at least one of the surfaces should be porous. As the tiles have already been used i'm guessing that they are no longer porous ? Should I still apply a coat of diluted pva to the wall before attaching the tiles ?

[jfgw]

The tiles will still be porous. Ready-mixed adhesive should be ok without primer or anything-else. Read the instructions if you are unsure.

If you use PVA in a damp area such as a bathroom or shower, expect the tiles to fall off. It is not the correct stuff to use. If you need to use something, use proper tiler's primer.

I have some Unibond ready mixed tile adhesive & grout.

Not something I am familiar with. I usually go cement-based (dry powder mixed with water), especially for grout. I have memories of ready-mixed grout shrinking and needing more to be applied. If you use cement-based adhesive on plaster, you must apply primer first otherwise the cement can react with the gypsum.

Why did the old ones come loose? Is there a big enough grout line (Normally 2mm minimum for wall tiles)?

Julian F. G. W.

[richlist]

The Unibond ready mixed tub of adhesive /grout is specifically for bathrooms and showers. It says to apply diluted PVA to the wall prior to tiling.

Don't know why they came loose or how long they had been like it. The tiles have been there for 8 years and yes the grout is about 2mm. None of the others seem to have detached.

[jfgw]

The Unibond ready mixed tub of adhesive /grout is specifically for bathrooms and showers. It says to apply diluted PVA to the wall prior to tiling.

Do they specify Unibond PVA? Some PVAs are more waterproof than others. If you do use PVA, make sure it is the one recommended. That way, you will have some comeback when the tiles fall off again There is a lot of discussion on the 'net concerning the use of PVA in a shower or other wet area.

I believe tiling primer is usually either acrylic or a specially modified PVA.

Julian F. G. W.

[richlist]

It says 'Prime dusty or wooden surfaces with Unibond Super PVA diluted with water.'

As my wall is neither dusty or wooden I'm inclined to not use any PVA before attaching the tiles.

[staffordian]

It says 'Prime dusty or wooden surfaces with Unibond Super PVA diluted with water.'

As my wall is neither dusty or wooden I'm inclined to not use any PVA before attaching the tiles.

That's what I'd do.

I've used ready mixed adhesive/grout a couple of times to refix odd loose tiles and never had any problems after simply scraping old tile cement off the tile and wall, cleaning any dust and loose stuff then refixing.