hello

was just wondering why you should not tile onto painted surfaces.

I ask because MAPEI say to contact their tech depo regarding painted surfaces and using their ready mixed adhesives.??

just read the mapei site and it says can be used on painted walls provided the tiles are absorbent?? What tile types are absorbent?

thanks

Regarding the paint...it depends upon type and how well it is adhered..

Tiles that are absorbent are tiles that are not vitrified...

If the paint has'nt had a mist coat to seal new plaster it could debond with moisture from the adhesive

sorry WB what did you mean when you say mist coat? Are you on about when it was originally painted??

ta

Yes mate, a mist coat is thinned down emulsion to seal for the subsequent coats of paint but some just apply a thick emulsion coat which sits on the surface on new plaster, the moisture gets sucked out so quick the paint can be peeled off even after years of application

ok. so ive got 2 get the paint off.

thing is ive googled it and it looks like a problem to do, very difficult. how do you guys recomend i do it, --- paint removal chemicals.??

ta

Use a piece of duck tape stick it to the paint, leave for bit then pull off will give you an indication how well the paint is stuck

when you use tape make sure its not the easypeel masking tape as that will not pull the paint off

its a bad idea anyway even if the paint doesnt peel, paint shouldnt really be tiled over, its not just an issue of the paints adherance to the wall, its also the lack of suction in the paint surface can cause poor adhesion to the painted surface

theres no need to strip the paint, score it through so the adhesive is sucking into the substrate rather than not sucking into the paint

Thats why I use powdered addy

so if you use powdered addy on scored well stuck paint with say basic 250x200 ceramic tiles that is ok.?

ive got another bathroom. painted emulsion walls again.


so how deep should the score marks be.

ta

deep enough to break paint surface so your adh can get a hold of substrate

I always start with the ducktape test. If paint comes off with it then its all got to come off.

I use one of those really sharp 4 in wall scrapers. Normally does the job fairly quickly. Sometimes I also use a hot air gun to soften the paint a bit to help it along before scraping.

Rapid set adhesive also helps reduce the risk of the addy bringing off the paint.

sound

i was actually gona ask about them hot air guns. they are quite cheap to buy, any recomendations on which one.

ta

Mine's just a cheap Black & Decker one. Had it about 10 years now. Often comes in handy. Never actually used it to burn paint off, just soften things by warming them up a bit.

If you come across one from Aldi or Lidl they are good value as they come with a 3 year guarantee

I'd try and shift it with a sander