Tiling onto concrete render (one wall flat, other not so...)

[alexjb1989]

Hi all,

When ripping down the tiles, just the concrete render was left. It is relatively flat, so I'm thinking to just tile on to it. I've heard, as long as I use a cement based adhesive I do not need to prime it with anything... but others say i should (not PVA)

However, there are some larger holes in the wall, I would like to try and level off before tiling. Anyone got any good ideas? i was thinking of just using the tile adhesive..l Let that dry and then tile over the top?

I have had the plasterer recently in to do the ceilings, and I did ask him to do the walls, but he won't have time until after Christmas - and we need to get it finished ASAP. So I know the best option would be for him to do it (he said something about a tight bond, and then skim).

Has anyone got any ideas how to best work around it? Fill larger gaps with something? Or do I have a go at plastering myself? Or just sod it and go for it!

https://drive.google.com/file/d/1YA71MCSMcDuxEKJx_yq3D4JOR7Q8LF6S/view is the 'bad' wall , a few gauges taken out.

This wall https://drive.google.com/open?id=1Y3Z8N10awFITNca4RYPc2yYxjgduwfNd doesn't look too bad!

 

[Bonni]

The purpose of applying PVA or SBR to a wall before tiling is to change a high suction background to a low suction background. That means, a high suction background sucks the moisture out of the adhesive/filler/plaster. So for example, on new plastered walls, you always put a mist coat on before applying top paint coats and filler. If you try to apply filler to new plaster, it just sucks the moisture out and you can't spread the filler.

If you want to be safe, just brush the wall down with equal parts water and SBR. Then mix up some bonding and skim over holes and low spots. Then SBR over the bonding.

If ceramic tile, waterproof premix adhesive is fine, anything else, cement based powdered adhesive.

 

[alexjb1989]

thanks ever so much.

That makes me feel better. I will take your advice!