Tiling over damaged plasterboard

[TheGraham]

Hi peeps,

This is my first post here so please be gentle. On new years eve my partner and I rashly decided to remove an unpleasant looking fitted wardrobe. This has led to a spiraling project of redecorating both our bedroom and en-suite.

Unfortunately the norm for the area is for people to get trade men into do everything. We don't have enough money to do that, so although I have the plasterer coming later this week and intend to get someone to fit a new carpet for us I have ended up doing the work myself. All has gone well so far, with some friendly advice from some more competent friends, youtube and a good dose of diynot.com I have managed to remove the old shower, toilet, sink, refit new skirting, etc.

The first baffling problem I have come across happened when I removed the tiles in the en-suite. There were tiles on a large splash back area and in the shower cubicle. Where the tiles had been split to fit badly around pipework coming through the walls I think they had been adhered with an insane amount of tile adhesive. After 15 years these few tiles were very difficult to remove from the wall and left some damage to the plasterboard. There is a patch on the splash back where there is a football-sized hole. In the tile area there is an area where the paper cover on the plasterboard had pulled away and some of the plasterboard has crumbled.

So I have a couple of questions. I've looked on the internet for answers and there are plenty. Unfortunately they're sometimes contradictory and I'm left a bit baffled.

So my first question is this: for the hole in the splashback plaster board, can I just cut a new square, and fit some wood battens behind it and tile over the lot? Is this a good idea or will it not be strong enough? These will be standard 30cm glazed ceramic tiles, so not too heavy.

My second question is: Can I just fill the crumbled section in the plasterboard with some deep filler? Will the tiles adhere okay to this? And will it be waterproof enough? Or is it better to bite the bullet and pull off the plasterboard in the shower and replace it with aquaboard? Of course this will inevitably lead to some more questions . I want to do a good job and not have it leak or go mouldy in a few years.

Here are some pictures. I would really appreciate any advice you have to offer on preparing these walls for tiling?

Untitled

• TheGraham
• 25 Jan 2014
• 1

Untitled

• TheGraham
• 25 Jan 2014
• 1

Thanks in advance,


Graham

 

[roughcaster]

Pull the plasterboard off in the shower and replace it with aquabord. With the damaged, crumbly plasterboard, remove that too, trying to fill it with filler is a waste of time, it'll never be a strong job. Square up and cut out the damaged area, then fit timber battens so that all edges are supported, then cut a new piece of plasterboard and screw it to the new battens. Make sure you use the same thickness of plasterboard, 9mm or 12.5mm. When you've fitted the new piece of board, you can put tapes over the joints, but because you're re-tiling, there's no need to be to fussy. Just fill up any gaps in the joints around the patch, put a tape over it, let it set/dry and that's it. Never tile onto any damaged/unsound surface.

 

[TheGraham]

Hi Roughcaster,

Thanks for the reply. I will do as you suggest with the the football-sized hole. Other than this, does the wall in the pictures look in a good enough state to tile to you? It's reasonably flat now that I chipped away much of the old tile adhesive.

Fitting the aquaboard concerns me a little more. I don't doubt it is the right thing to do, but how do I fit it in an outwardly facing corner where it meets the normal plasterboard (i.e. a sticky outy corner )?

Also, the missus has specified floor to ceiling tiles. I guess this is fine, but will the tile adhesive adhere to the bathroom paint okay? Or should I be scraping all of this off too?

Again, thank you for the reply.


Graham

 

[roughcaster]

The rest of the plasterboard looks ok from what can be seen, although if there's any doubt, replacing would be the best bet, you only want to do the job once. Can you put up another pic regarding the "sticky outy corner".
Tiling onto paint? Better asking that question on the "Tiling Forum", the guys on there will advise you as to the best way forward.