How to prepare shower wall to be waterproofed?

Lindsey

I have taken out the old bath and are replacing with shower. The wall are paint over plaster.I need to waterproof the shower area. The plaster is very hard to remove and there is small amount in the wall left. How much must I remove before I can prime and wet wall?Do need wall cleaner

JacobZ

Hi @Lindsey,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

As the plaster would be fully encapsulated by the waterproof membrane, as long as it is flat, stable and will not fall off the wall, then you can apply your membrane over it. Looking at your photos, I think you are pretty close at this point. 

You may want to put a bit more work into this area where there is still paint, but other than that it looks pretty good.

Once you are happy that there is no particularly loose material, you'll want to brush and vacuum the wall to ensure there is no dust before priming it with a suitable primer such as this Bastion 5L Waterbased Primer. 

You can then apply your waterproofing membrane over the top.

Let me know if you have any further questions.

Jacob