Levelling slightly uneven wall before tiling

Hi guys

Bathroom is almost ready to tile. Ive done my homework and have a few questions which I hope you can help me with.

1. One of the walls has been rendered by my plasterer with a sand and cement mix. Can I tile straight onto this and do I need to use any special sort of adhesive?

2. The other wall was tiled half way up and ive stripped these tiles off. When the tiles came off the plaster came with them so I am left with a wall which is half old cement/sand render at the bottom and half plastered at the top with the plastered part being slightly prouder.

Could I use bonding coat to skim over the rendered half to bring it level?

The wall is a solid internal wall if that matters.

Thanks in advance

gaz2923 said:

1. One of the walls has been rendered by my plasterer with a sand and cement mix. Can I tile straight onto this and do I need to use any special sort of adhesive?

Click to expand...

Yes you can. It’s an excellent tile base as long as it’s flat but what type/size/weight of tiles do you have? This will also dictate which type of adhesive you need to use.

gaz2923 said:

2. The other wall was tiled half way up and ive stripped these tiles off. When the tiles came off the plaster came with them so I am left with a wall which is half old cement/sand render at the bottom and half plastered at the top with the plastered part being slightly prouder. Could I use bonding coat to skim over the rendered half to bring it level?

Click to expand...

No; do not use Bonding plaster is unsuitable for a tile base. Generally it’s not advisable to use any sort of plaster as a tile base, it can slow your project down as it must be fully dry before tiling but. more importantly, it has weight restrictions which could be critical if you’re planning on using large format/heavy tiles. Large format tiles need a very flat tile base.

Use a cement powder based adhesive to fill out & level (which you also need if using large format tiles or a quickset render.

Thanks

My tiles are 30x40 ceramics so they are quite big.

For the floor I've used bal rapid flex but it's pricey - I paid the price as it is floorboards with hardy backer so I wanted to be safe. Walls are different though and no issues of flex so can anyone recommend a good powered adhesive which isn't going to break the bank?

One more question - my plumber said PVA the walls - should I do this or apply without PVA?

One wall is sand cement render and the other is old plaster

gaz2923 said:

Walls are different though and no issues of flex so can anyone recommend a good powered adhesive which isn't going to break the bank?

Click to expand...

BAL Rapid set will do you over render or plaster but plaster must be acrylic primed. I assume you’re aware of the short pot life of Rapidset adhesive!

Don’t skimp on quality, you tend to get what you pay for with tiling products.

gaz2923 said:

One more question - my plumber said PVA the walls - should I do this or apply without PVA?

Click to expand...

Ignore your plumber’s advice, he doesn’t know what he’s talking about & should stick to plumbing. Never use standard PVA on any tile base, especially in a wet area. It remains water soluble & if it gets wet, your tiles will fall off. If you need a primer use an SBR/acrylic primer but always follow the adhesive manufactureres instructions regards priming.

gaz2923 said:

One wall is sand cement render and the other is old plaster

Click to expand...

30 x 40 ceramics are large, how much do the tiles weigh per/sqm? If not tell me what thickness they are. I can tell you now that they will most likely be too heavy for even a new plaster finish, let alone an old one which may have dodgy adhesion.

You will also need very flat walls & use the correct size trowel if your going to get the tiles level & looking good.