No tanking and tiles not stuck - Last owners efforts

[Cooop]

I'm refurbing the ensuite, I am not a professional but based on other work that the previous owner took on I knew it wasnt going to be pretty....

The tiles were not stuck to the plaster at all, once one was off the others could be pulled off by hand with minimal effort leaving no adhesive apart from two tiny areas. Makes it easier for me to re-tile but poor previous effort.

As the tiles around the shower were removed there was no sign of any tanking what so ever, at the bottom right its been soaking the plasterboard behind the skim for a long time. The back of plasterboard pushed though by hand and the back was mold ridden. The left corner isn't as bad as the photos make out, the dark marks are surface stains but need to check it out further tomorrow to see how much I've got to replace.

I guess the tiles didnt stick as the adhesive was rubbish or he didnt seal the plaster after the skim - any ideas?

 

[Doggit]

Repair the damage, tan the shower area, PVA the rest, and then do a test row of tiles to make sure you've got the right adhesive for the tiles you're using.

 

[jctilingservices]

agree with doggit on everything except for the use of pva, use an acrylic sealer, not a water based one in my opinion

 

[Doggit]

Very good point jct, yes, I should have thought of that.

 

[diydazzler]

How important is a primer/sealer ?
I've just tiled 1 wall on fresh plasterboard.I didn't use any sealer.On areas where there's some adhesive that I haven't yet tiled I've scraped it off but it's been a bugger.It's certainly stuck well enough !

 

[Doggit]

It can be very important, but not wanted on paper faced plasterboard. A sealer can close off the pores of a substrate so that moisture doesn't get sucked into it too quickly, and it can also seal in any dust on the top layer that would stop the adhesive sticking. But as jct reminded me, you need to use the right one.

 

[jctilingservices]

It can be very important, but not wanted on paper faced plasterboard. A sealer can close off the pores of a substrate so that moisture doesn't get sucked into it too quickly, and it can also seal in any dust on the top layer that would stop the adhesive sticking. But as jct reminded me, you need to use the right one.

If tiling directly onto plasterboard no sealer / primer is necessary, if its a shower area then tank it, personally I wouldn't use plasterboard in a shower area. plastered walls are best sealed / primed as they seal the pores as Doggit says and stops the moisture being sucked out of your adhesive to quickly therefore you adhesive would not have the required hold on the tiles as needed

 

[L95]

Repair the damage, tan the shower area, PVA the rest, and then do a test row of tiles to make sure you've got the right adhesive for the tiles you're using.

All correct except for the PVA. Use acrylic based as PVA will go live again and debond (and your tiles with it) if any moisture comes through. If you're using a size larger than 30x30 then you need powder based adhesive.

agree with doggit on everything except for the use of pva, use an acrylic sealer, not a water based one in my opinion

+1

 

[Cooop]

Thanks for the advise everyone.

I ended up using Weber PR360 for the primer on most of the walls, the tanking kit came with its own primer so used that around the shower area.