Tile backer board, tanking or just apply the tiles to what is there?

[Tog-]

I have started a bathroom renovation and it won't be long before I need to start tiling, but I'm just going round in circles and could use some input from others, if you would be so kind.

All my internal walls are block with some kind of "screed/render" over the top.
I have removed the old tiles which in some areas took the plaster with it and in others left the plaster and adhesive in place.
How would people go about prepping this for tiling?

Install a tile backer of some kind all along this wall and on the boxing in at the shower end? If so how do you attach the backer boards to this type of wall? Drill through, push a plug through and mechanically screw the board to the wall?

Would you go for a paint on tanking? Maybe scrape off the old plaster and add the paint on tanking all around the bath area then just tile onto the wall?

Or finally would you just tile over what is there now without any further prep?

I thought the backer board was the route to take, but as I said I seem to just be going in circles in my own head.

Any input would be gratefully received.

 

[Wayners]

My bathroom is completely tiled on plastered walls with concrete blocks behind.
1 wall at bath end is tiled plasterboard which has the built in shower mixer and head.

I fitted in 2007. All good.
Used whitestar adhesive and bal grout. Sealed walls with bal sealer prior to tiles

 

[simplesteve]

Hi Tog. Well, you have a few options. Depending on the answers to the following what I would suggest:-
1. What kind, size, and weight of tiles are you putting on ?
2. When you rotate an 1800 level all over the wall, how flat/ plumb/ dips has wall.
3. Are you taking the bath and sink off the wall ?

 

[Tog-]

Hi Tog. Well, you have a few options. Depending on the answers to the following what I would suggest:-
1. What kind, size, and weight of tiles are you putting on ?
2. When you rotate an 1800 level all over the wall, how flat/ plumb/ dips has wall.
3. Are you taking the bath and sink off the wall ?

Hi Steve,

Current thinking is 600x300 tiles weighing approximately 3.3kg each.

The wall is actually fairly flat, I hadn't checked until you asked this question, there are some dips where the old plaster has come off, but we are talking 1/2mm.

I will be removing bath and sink to replace with new units. Wall hung vanity will replace sink and a similar sized bath to replace current bath.