Weight limit an issue at low tile height?

[monkeyhanger]

I am doing out my bathroom in quartz 30cmx 30cm tiles which weight 2.15kg each.

Im tiling 2 tiles high around the bath (so a height of 55cm (below bath rim) to 115cm exc gaps and trim).

The wall that spans the length of the bath is plastered 12.5mm plasterboard which was cemented onto blockwork.

Does the weight rule of 20kg/m2 apply when the tiled area is only 0.6m in height?

Should I be hammer fixing some studwork to the block wall and then aquapanel on top of the studwork for the tiles to fix to? This would bring out the tiled part of the wall out by 60mm-ish, which isn't ideal.

What would a pro do for a job they'd be putting their name to - tile straight onto what's there as it's only 60cm tile height, or put the studwork in?

[faithhealer]

A brave man to admit tiling over weight but I would imagine most have 'crept' over the limit before. mmm two tiles high, would still hurt a child. I've walked away from tiling full walls before but have stuck a 200mm high stone tile for a splashback before. If I was doing it for you I would refuse.

[Dan]

I don't think it's just to do with falling off and hurting somebody, it's just a case of them not staying on, so there'd be no point in tiling it.

If there are no kids around, let it be and see how long they last.

[deanotile]

i will get hanged for saying this but i have knowingly gone over the recommended limits on several occasions. not by a lot but sill over (at the customers request) but if it was my house I'd remove the boards back to the block work and glue and screw a tile backer board.

[Scott]

Ive done it too. Ill put my hands up

[david campbell]

can't see it being a problem,think of the size of a full sheet of palsterboard(2,1/2m2) i think ! these weights refer to being spread over that not small areas where there is no stress above,the entire top half of the sheet will be under no stress at all

[Phil Hobson]

I have never exceeded the recommended weight limits ever, ( I have my fingers crossed behind my back) I hope that counts, but seriously it can be dangerous

[Dave]

It will be around 25kg with addy and grout.. not the end of the world weight wise at that height...limit is 20 kg..

[Scott]

I guess it depends on how good the plaster is

[TheTiler]

I'd add to Scottleys comment - it all depends on the initial bond of board to blockwork. Which the tiler didn't do. If it was a builder who did it, I'd walk away as they think tilers are fussy.
If I was asked to tile your walls, I'd try to pull off the boards with most of my weight. I'd also make sure it wasn't lightly spot-fixed with isolated areas also.
This would probably lose me the job when I fell on my arse...

[monkeyhanger]

The plaster looks like thistle multi finish or similar. If I were to pull the old board down (and the cement type stuff it'll be stuck to the blockwork with), would I be better just sticking an unfinished plasterboard back up there (32m2/kg - well within limits) to the blockwork? If so, what's the best stuff to stick it back up with.

Seems a mixed bag of opinion whether to chance it.

Do I need to do any tanking with a bare plasterboard? The bath has no showering going on above it (and never will, we have a separate ensuite shower), so the tiles won't be getting wet apart from the occasional accidental splash at low level.

Any other tile backer board makes that can be bonded to the blockwork (and with what)? I have some aquapanel for the studded walls, but am under the impression these need to breathe via studwork fixing - so not suitable for bonding to the blockwork directly - right?

Judging by the way another plasterboard sheet was attached to the blockwork with some cementious compound in the newly finished shower cubicle (which I stripped out and studde then aquaboarded, I'd say this board will have been well bonded to the blockwork also.

Thanks to everyone for the input/advice so far.

[monkeyhanger]

Dave: Could Kerdi board be the way to dot and dab easily? If so, do you know where around Newcastle sells it? I'd be doing a 1900mm wide x 700mm high area, so what size boards do these come in, and what's a ball-park price for supply?

Alternatively, could I chip/scrape off the plaster skim on the current plasterboard (so it's reasonably flat and use Fischer hammer fixings to screw aquapanel over the top of the plasterboard and into the blockwork behind it? The resultant board would only be 6 - 8mm proud of the current board.

[Scott]

If you dot and dab anything to it you will have to mechanically fix as well, other wise you are adding more weight to the skim.

You could use concrete screws instead of fishcer fixings, its a lot cheaper as they have no plug and just a pilot hole and drive them in

[Dave]

Dave: Could Kerdi board be the way to dot and dab easily? If so, do you know where around Newcastle sells it? I'd be doing a 1900mm wide x 700mm high area, so what size boards do these come in, and what's a ball-park price for supply?

Alternatively, could I chip/scrape off the plaster skim on the current plasterboard (so it's reasonably flat and use Fischer hammer fixings to screw aquapanel over the top of the plasterboard and into the blockwork behind it? The resultant board would only be 6 - 8mm proud of the current board.

It would yes and north yorkshire tiles on shields road or just down from CTD sells it..


You could just cut out the section you need and use plasterboard as you say..

[monkeyhanger]

OK, so plasterboard or Kerdi board stuck by dot & dab and screwed in to the blockwork also seems the easy solution and keeps the new section of board no further out than the rest of the wall. May seem a daft question to a pro, but what specific stuff would you use to dot and dab?

So Kerdi or plasterboard? I'm under the impression that if this was going in a shower cubicle then it'd be Kerdi, but around a bath is untreated bare plasterboard ok?

[Dave]

Use Plasterboard adhesive..

[Scott]

You could tank the area with a paint on gum such as Mapeigum.

[monkeyhanger]

OK plasterboard adhesive it is then - just got to chip the old stuff off - that's an epic job in itself!

I wish i'd bought less wood for the studwork on the other 2 walls now! I'll find a use for it somewhere.

Don't think i'll tank on a bath that gets used nowhere near as much as the shower. Good grout and good seal around the bath rim should be ok for me.

Why do these new house builders bother plastering over a board they know they're going to be tiling over (assuming the board is flat and level)?

Thanks again to everyone for the advice.