Please help. Bathroom wall tiling preparation advice. 30s house.

[Aethelweard]

Dear Tilers

Hi all, I've just joined the forum. I am renovating my 30s semi. I am a diyer and I have just removed some original tiles from a 1932 bathroom in my house. They were in bad condition and cracked so had to go sadly. Thing is, I want to retile, probably porcelain. Underneath the tiles was a mortar about 13mm thick and underneath that, attached to the brickwork, a render, presumably cement based, about the same thickness. Most of the render is still attached to the brick. It is not blown. In some places it has come off exposing brickwork. Should I just remove all the render, scrape the brickwork and redo it all as it was or do you think I can work with the existing render by patch repairing it and then remortaring new tiles on top of this? I feel slightly out of my depth (it's a familiar feeling ☺️) but with some experienced advice I think I could do this.
Best, Simon

 

[Slippery]

Personally, I would dot and dab a plasterboard (if it's not inside a shower) over the entire wall, take a bit of time to get it perfectly level/plumb and straight/square, then use SBR primer and the tiling will be a doddle, trying to tile over what you have would be very difficult.

if it is in a wet area, use cement faced tile board instead

 

[Aethelweard]

Personally, I would dot and dab a plasterboard (if it's not inside a shower) over the entire wall, take a bit of time to get it perfectly level/plumb and straight/square, then use SBR primer and the tiling will be a doddle, trying to tile over what you have would be very difficult.

if it is in a wet area, use cement faced tile board instead

Hi Slippery, thanks very much for your reply. I've been away so haven't had time to respond to you until now. It is in a shower/bath area, yes. The situation is a difficult one I agree. Have never used tile board or even plasterboard before. In fact, I've only ever tiled a hearth before! 😊 I need to tile above the area where the old tiles have been removed as well for the new shower that is going in. This wall area has a plastered finish which is I think a skim on top of the cement based render as you can see from the new photo. Starting to think that your tile board idea is the safest option not least because filling in the exposed brickwork areas with patch repair render or even bonding will be messy and hard to achieve a good enough base for tiling. Many thanks, Simon