Old plaster came away, render looks solid and flat what do i need to seal it with prior to tiling?

[paul cumpo]

Hi All,
Have just started removing the tiles in an old bathroom and the plaster is coming off with the old tiles but the render remains in tact and in decent condition, the surface appears to be solid, dry and flat.
Do I need to apply a primer prior to tiling? is a fairly wet room so don't want to make any errors in preparation but also on a fairly tight budget.
Added a photo of the area.
Thanks in advance for any advise.
Paul

 

[Qwerty]

Remove all plaster down to render. Brush or vacuum down, seal with an acrylic primer or SBR and then tank if required

 

[Flintstone]

Bonding coat plaster ?

 

[Dumbo]

Bonding coat plaster ?

Think you're right doesn't look like sand and cement to me

 

[Time's Ran Out]

Yes that’s just a scratch coat.
So who does what on this surface?

 

[Dumbo]

Yes that’s just a scratch coat.
So who does what on this surface?

According to a lot of adhesive manufacturer's you can't tile this as it the the first part of a 2 part system.

 

[WetSaw]

Depends on what is going on it. Skim it, overboard, so many choices!

 

[paul cumpo]

yeah it could be a first skim of plaster, ideally wanted to seal it then tile straight onto it, would have been there years.

 

[WetSaw]

Regardless of how long it's been there you can't tile onto bonding.

 

[paul cumpo]

so am I better applying a thin top coat to it before plastering or do I need to remove it all and board, assuming the 2nd one is the most costly

 

[WetSaw]

It's often easier to overboard, you then have a perfectly flat and plumb surface.

 

[paul cumpo]

Ok ive made the decision to remove all the bonding or first skim (whatever its best know as) and go back to the brickwork. Ive done a fair bit of plasterboarding but never aquaboarding and to me this looks an expensive option and could be tricky to do around the window area so thinking it might be cheaper to plasterboard and then tank the area around bath/shower.

 

[Qwerty]

A good option. This way you can ensure levels and is actually the most cost effective way

 

[paul cumpo]

Ive never tanked an area before.does it consist of taping the plasterboard joints and then painting the area with a waterproof sealer?

 

[Qwerty]

Ive never tanked an area before.does it consist of taping the plasterboard joints and then painting the area with a waterproof sealer?

Pretty much yes. A good kit for DIY use is Mapei Mapegum WPS which is widely available all over the place. Good demo videos on YouTube

 

[Time's Ran Out]

At £50 for a tanking kit it would be cheaper to fix Wedi board .

 

[Dumbo]

At £50 for a tanking kit it would be cheaper to fix Wedi board .

But is it cheaper once you tape the joints and waterproof screws ?But I'm with you in that i would fix tile backer board if I was at that point .

 

[Qwerty]

At £50 for a tanking kit it would be cheaper to fix Wedi board .

Add p&p into the equation if nowhere local, DIYer paying retail prices and it may well not be cheaper

 

[Perry]

You don't need aquaboard.

 

[Flintstone]

Tilefix direct for all the boards and fixings, price it up. Better than a tanking kit.

 

[Qwerty]

IMO dry lining the whole room with plasterboard and tanking only the shower area is more cost effective than tanking boards and tanking tape/ paste for the joints.

Don't get me wrong, tanking boards are superior all day long, but when cost is a consideration then dry lining the whole room is cheaper.