What was used on this wall and does it need to be removed?

[pgabriel]

Hi,

We bought a 1950s semi which needs complete refurbishment. The bathroom previously had vinyl wallpaper which we have taken down. Underneath we found the grey plaster as everywhere else in the house but on top of that two or three layers of what looks like paint and I assume was to prevent moisture from getting into the walls. These layers are in varying state of repair (see pictures) - largely fine on the outside wall but pretty poor on the internal walls.

The plan is to tile the bathroom and I am wondering if you could tell me what these layers are, if we need to remove them or not and if so how best to do it.

Many thanks,
Paul

[dewaltdisney]

Looking at the pictures is it that god awful textured paint they had in the 80's?. The grey looks like the finish plaster coat and that looks like a thick paint cover under. The logic of this is that if you tile over you must be satisfied that the adhesive is going to bond well enough to support the weight of the tiles. So in this situation you are looking at sticking the tiles on the textured paint which is in turn stuck to the pink paint that is in turn stuck to the finish plaster.

Personally, I think there is an issue if you intend to use those big tiles that are fashionable these days as the weight is a factor for the adhesive to support. Having said this I have tiled on paint in the past with no issues so I would have a go at removing anything loose (with your new scraper) and make sure that the surfaces are all sound. Next give it a good scratch to break through to the plaster surface and to give a good key. You can make up a scratch block out of some wood with nails punched through or some carpet gripper. Do not use premixed tubs of adhesive and mix up your own using a dry mix in usable batches. DO NOT LISTEN TO ANYONE WHO TELLS YOU TO PVA THE WALLS that is a no no.

Good luck

DWD

[pgabriel]

Thank you! Yes the grey is the plaster coat. The pink (other parts of the room have a yellow layer) could well be from the 80s. The white looks like it was done later (top of the first picture you can see it being painted directly on the plaster where the pink layer was broken) and is so thin that I don't think it was intended as paint but perhaps a seal or primer for the vinyl wallpaper...

Apart from the tile adhesive is there anything else the bathroom walls should be treated with? I've seen your point about PVA so just stick a suitable alternative on top of the existing 'paint'?

[dewaltdisney]

No, I do not think so. A good scratch with allow the adhesive to grab the wall plaster surface rather than just the paint. I always use this firm https://www.wallsandfloors.co.uk/ as they are excellent and you know they will have the stock.

DWD

[Bob225]

it looks like very thin re skim and its been mist coated (looking at the brush marks in the second picture) I take it had wallpaper covering that mess ?

scrap them tiles off the ceiling and double tack (plasterboard) and skim