Weight limit on painted plasterboard

[Shooter999]

Hi All,

We're currently looking at 600 x 300mm porcelain tiles for our bathroom. The majority of the room is currently painted skimmed plasterboard (which is attached to stud and exterior wall )

From reading other threads, it seems we may have some issue with the weight of the tiles?

Is there a link which shows the weight limit?

If our tiles will be too heavy, what options do we have ( please list all, even if they may be extreme).

Thanks in advance.

 

[Old Mod]

Plastered PB is 20kgm2 WITHOUT paint.
Unskimmed is 32kgm2
Hardibacker board 100kgm2
Tilebacker boards around 50kgm2 (manufacturer dependent)

Porcelain is approx 2.4kgm2 per mm
Adhesive and grout approx 4kgm2

 

[Shooter999]

Hi @3_fall thanks for the prompt reply.

What does the PB refer to in point 1?

What effect does it being painted have, is it that the weight limit will be reduced by the weight of the paint?

Regarding our options assuming we're going to have 600 x 300mm tiles which will be over the weight limit.

1. Remove all existing plasterboard and replace with new unskimmed plasterboard.

2. Overboard throughout with either hardiebacker or some other tile backer board

3. Go ahead and tile onto existing painted PB.

This tiling malarkey ain't half complicated, and I haven't even started to think about setting out / laying the tiles yet.

 

[Old Mod]

PB = plasterboard.
You shouldn't tile over paint, it can very easily debond from the wall, leaving you with a pile of tiles on the floor with paint stuck to the back.
You can overboard with a lightweight tile backer board like Delta board.
Or remove the paint, but that's still over the top really.
Or you can use a thin porcelain tile (4-6mm), after removing the paint.

 

[J Sid]

the weight limit for painted plaster is 0 kg m2

 

[Flintstone]

This is the same problem I see all the time and there is no easy quick fix, everyone wants nice porcelain tiles instead of ceramics ofcourse. Best bet is to over board the lot, with plaster board or tile backer board, then tank the shower area

 

[Flintstone]

Deffinately don't be tempted to tile on the paint .

 

[One Day]

Overboard with delta board / wedi board / kerdi board (lightweight tile board) NOT hardibacker / aquapanel.
Easy to screw 6mm boards into studs using washers, but on dry-lined walls you'll need to dot and dab onto your existing walls, noting where the dabs are and drill through them afterwards into the block using some frame fixings, again with washers.
That's the only way I would tackle it.

 

[Shooter999]

Thanks all. The replies are really appreciated.

Overboarding it is then. I'll take a look at the various recommendations.

Have to say that the people on this forum are really helpful and friendly (unlike some other trade forums).

 

[Flintstone]

Are 6mm boards ok on walls, I thought 10mm was advisable

 

[One Day]

Are 6mm boards ok on walls, I thought 10mm was advisable

Comb adhesive onto the wall, fix the boards with screws into the studs and 6mm is fine.

 

[Flintstone]

So you need to use adhesive even onto stud walls?
I assume you need to comb adhesive onto solid walls too rather than dot and dab ?

 

[One Day]

So you need to use adhesive even onto stud walls?
I assume you need to comb adhesive onto solid walls too rather than dot and dab ?

6mm on its own would be useless onto studs, but over boarding existing painted walls, it's effectively just facing the walls. I'd use a 6mm trowel just to prevent any dips and hollows.

 

[Flintstone]

Just been reading on wedi website, says 12mm board direct to studs.

this bit puzzled me..

Before installing wedi Building Panel over any gypsum containing product, a primer must be applied prior to application of thinset mortar which is used to attach the wedi to such drywall assembly. Fasteners may be set in some areas to temporarily attach the two boards and compress the thinset adhesive. Do not forget to seal such fastener points with wedi joint sealant.

 

[One Day]

Which part is puzzling you?

 

[Flintstone]

It's suggesting you stick the board onto the wall with tile adhesive only, and you can use fasterners temporarily. I assume it means on to plaster

 

[One Day]

I've stuck Wedi and Kerdi onto blocks without backing up with fasteners, but on a skimmed wall or a render I was unsure of, I'd want fasteners in also!

 

[Flintstone]

That's what they are suggesting tho isn't it? Does it spread the weight of the tiles out, essentially making it like one large weight mass instead of individual tiles

 

[Old Mod]

It's suggesting you stick the board onto the wall with tile adhesive only, and you can use fasterners temporarily. I assume it means on to plaster

That's American Andy.
Things are done differently for all sorts of reasons.

 

[Flintstone]

How can something like that be so different ??
It does make sense, can some one find out ? Your a connected man Marc!

 

[Dumbo]

To my mind on a skimmed wall you would need mechanical back up or else you just as well tile straight onto the skim .
By the way any body considered how horrible some of this work is going to be to take apart when someone wants to change their Tiles

 

[Old Mod]

How can something like that be so different ??
It does make sense, can some one find out ?

What makes sense?
Temp fixings?
Safer to leave them in.
Personally wouldn't fix boards to a wall without them.

 

[Flintstone]

It makes sense to me that it spreads the tile load out when you stick a board on, I don't do over boarding etc but it's something I'm interested in offering.

 

[Perry]

Take the plasterboard down and replace it with new. Would this be the easiest and cheapest option?