Tiling prep advice please

[rarara]

Hi,

I recently had a wall in the kitchen skimmed (was a combination of old brick/plaster and some areas boxed-in so just new plasterboard). Since, so far it has had the following done:

1) Couple of coats watery emulsion onto the new plaster
2) Coat of dulux endurance silk (wipeable)

I now want to put some tiles up as a splashback. These will prob be smallish (10x20 or so). My most recent tiling job was done with no-nails type of stuff, and for convenience I might use that again. Do I need to do anything or will the smooth painted finish be sufficient?

thanks

 

[PrenticeBoyofDerry]

I would sand the paint down, in the areas covered by the tiles, so you score in to it, this will give you a better key between wall and adhesive, use a proper wall tile adhesive not no-nails! No-nails will likely cost more too!
A professional adhesive like BAL would be recommended.

 

[Richard C]

Small tiles shouldn’t present too much of a problem but if your going to tile you really shouldn’t paint; the only thing holding the tiles up will be the bond of the paint to plaster.
As the paint you’ve used is also washable, it’s going to be pretty much water proof which may extend adhesive set time considerably &, as PBD advises, you will now need additional prep. If at all possible remove the layer of washable paint by sanding, if not sand & score through the surface to the plaster with an old scraper.

I would not advise no nails or any grab adhesive, it’s not designed for fixing tiles; it will be more expensive, sets very hard & shrinks back when set. Use a quality trade tub mix adhesive such as BAL Grip or White star & an antibacterial grout such as Microflex.

Or you could use a powder cement adhesive which is chemical cure rather than evaporative; the paint must be well stuck on though, test with a piece of Gaffa tape.

 

[tpt]

word of warning on the grab adhesive - some of them have a heavy dye content and this dye can get sucked through the ceramic backing and show under the glaze on the tile front - dont do it.
If you must do this sort of thing use clear silicone - but both will be dearer than good old tile adhesive

 

[rarara]

thanks for the advice all. needed to paint since wasn't sure how long the area would be tile-free so wanted it to be wipeable around the worktop. reckon scoring is easier, rather than sanding, so will go with that

will use tile adhesive (only used no-nails previously since the tiles were 20x60 so fell off using adhesive) if that is the recommended

 

[Symptoms]

rarara - an effective method of scraping and keying a painted surface is to use the teeth on a saw ... no, not your best cabinet makers tenon saw! Swing by your local diy shed and buy a short cheepo hardpoint for about £3 - £4, this should be used with the blade tilted to about 30 degrees to the painted wall and then 'saw' off the paint.

Take care not to go too far into the plaster ... it'll work a treat.

 

[Richard C]

only used no-nails previously since the tiles were 20x60 so fell off using adhesive

My guess is you used the wrong adhesive & probably cheap DIY rubbish; with tiles that size/weight you need to use a powder cement adhesive, tub ready mix is not suitable; you must also use an acrylic primer with cement adhesive over gypsum plaster.

If your doing any more serious tiling I would advise you read the tiling sticky & forum archive posts, it will prevent you making basic mistakes that usually end in tears.