Different Wall Types In Shower Cubicle - Tile Advice

[Land Man]

Hi all

Please can you advise - I'm looking to fit a new shower cubicle in a recently converted outbuilding. One wall is masonry which has been plastered in the traditional way (bonding and a skim) and the other wall is 12.5mm moisture resistant (green) plasterboard which has been skimmed. I was looking at putting the small 'brick bond' 2" x 4" travertine tiles in there but i think these might be too heavy (10mm thick)?

My questions are:
1. Can i tile directly on to the plastered masonry wall? If so do i need to prime?
2. Can i tile directly on to the skimmed moisture resistant plasterboard. If so do i need to prime?

Any advice much appreciated.

 

[magga]

1. Yes and yes. Better to tank it first really if it's for a shower area though.

2. Yes again, but the weight limit of skimmed plasterboard is 20kg per m2. Again, better to tank it first.

 

[White Room]

I'd be giving the plastered wall a few taps to see if it's hollow, as you say the weight would be exceeding the recommendation.

 

[Land Man]

1. Yes and yes. Better to tank it first really if it's for a shower area though.

2. Yes again, but the weight limit of skimmed plasterboard is 20kg per m2. Again, better to tank it first.

Magga, thanks for the swift and concise response. When you say 'tank it' what exactly do you mean? I'm intending to install a standard shower tray and not a wet room. Cheers

 

[Land Man]

If i don't tank it what do you recommend i prime it with?

 

[Land Man]

I'd be giving the plastered wall a few taps to see if it's hollow, as you say the weight would be exceeding the recommendation.

Thanks Whitebeam - plaster is sound as it was exposed brickwork and only recently plastered.
Is the weight issue more relevant to the floated plaster wall or the plasterboard on studs?

 

[magga]

I would use Ardex WPC or Mapei Aquadefense tanking products. They are similar products and are basically a paint/brush on mix along with corner/joint tape which waterproofs the area, so when the inevitable happens, your PB doesn't fall apart behind the tiles. Even though it may not be a wet room, I would still recommend it for the sake of £50-£60 and a few hours work.

Also, what whitebeam has said is good advice, make sure the wall is sound with no loose plaster.

Plasterboard can take 32kg/m2 I believe, skimming it actually reduces it.

 

[Land Man]

I would use Ardex WPC or Mapei Aquadefense tanking products. They are similar products and are basically a paint/brush on mix along with corner/joint tape which waterproofs the area, so when the inevitable happens, your PB doesn't fall apart behind the tiles. Even though it may not be a wet room, I would still recommend it for the sake of £50-£60 and a few hours work.

Also, what whitebeam has said is good advice, make sure the wall is sound with no loose plaster.

Plasterboard can take 32kg/m2 I believe, skimming it actually reduces it.

I don't really understand how this would work when using a shower tray - say the tileing fails and water gets behind the tiles and adhesive and runs onto the tanked plaster finish. The water will run down the tanked wall, behind the shower tray and onto the floor where it will get into the bottom of the board resulting in the board getting wet...?

 

[magga]

You would tank the wall, but use the tape to the top of the shower tray, so nothing would get past that point.

View: https://m.youtube.com/watch?v=aHPMInq1SGQ

 

[White Room]

Thanks Whitebeam - plaster is sound as it was exposed brickwork and only recently plastered.
Is the weight issue more relevant to the floated plaster wall or the plasterboard on studs?

The same for each wall 20kg per square metre.

 

[White Room]

You would tank the wall, but use the tape to the top of the shower tray, so nothing would get past that point.

View: https://m.youtube.com/watch?v=aHPMInq1SGQ

That is nearly exactly how I do it but didn't learn it off Mapei...

 

[magga]

What do you do differently, just out of interest?

 

[White Room]

What do you do differently, just out of interest?

I leave everything as it is until I have tiled, then cut very close to the tiles with a new Stanley blade angled so when I silicone there is no tanking showing thru.

 

[magga]

That's a nice idea, think I'll try that next time