Unsuitable walls - Tile Advice

[Rickm34]

Hi there. So i have a job coming up. 5 fully tiled bathrooms. Glazed Porcelain tiles 300 x 600. First bathroom is 'ready'. Went to price it up. Tiles are a discount lot. 2 batch numbers which isnt a problem, but no box weight. So 2 walls in the first bathroom are skimmed plaster on pb. ( in my opinion tiles way too heavy for skim)I manage to stop them doing anymore. The remaining walls are bare pb, and bare pb in the other bathrooms.

Im using tilemaster extrabond standard set on walls
And tilemaster setaflex rapid on floors
Tilmaster grout 3000 grey flexi
And tilemaster prime plus

So i informed the builder who was oblivious to weight issue, and said it will be reet tiles wont fall off.

Im not happy about the 2 walls but he is adamant it will be fine.

I was planning on producing a waiver that the builder could sign that i have informed him of weight issues but that the builder is happy to proceed. How much weight will this hold, if you excuse the pun.



Anyone every done something like this?

Also in regards to the primer would you prime the plaster skim?

 

[LM]

Hi there. So i have a job coming up. 5 fully tiled bathrooms. Glazed Porcelain tiles 300 x 600. First bathroom is 'ready'. Went to price it up. Tiles are a discount lot. 2 batch numbers which isnt a problem, but no box weight. So 2 walls in the first bathroom are skimmed plaster on pb. ( in my opinion tiles way too heavy for skim)I manage to stop them doing anymore. The remaining walls are bare pb, and bare pb in the other bathrooms.

Im using tilemaster extrabond standard set on walls
And tilemaster setaflex rapid on floors
Tilmaster grout 3000 grey flexi
And tilemaster prime plus

So i informed the builder who was oblivious to weight issue, and said it will be reet tiles wont fall off.

Im not happy about the 2 walls but he is adamant it will be fine.

I was planning on producing a waiver that the builder could sign that i have informed him of weight issues but that the builder is happy to proceed. How much weight will this hold, if you excuse the pun.



Anyone every done something like this?

Also in regards to the primer would you prime the plaster skim?

Skimmed plaster can only hold 20kg per square metre, it's one of the worst substrates to tile on and yes it must be primed with two coats of an acrylic primer, never ever use PVA.
Plasterboard can take 32kg per metre squared, also prime.
Would it be possible to over board the skimwd walls with some mechanically fixed backer board or at worst plasterboard?
The waiver wouldn't be worth the paper it's written on here, fundamentally you are responsible because you know you should not be tiling on a substrate that can't take the weight. You'd loose in court.

 

[Rickm34]

Skimmed plaster can only hold 20kg per square metre, it's one of the worst substrates to tile on and yes it must be primed with two coats of an acrylic primer, never ever use PVA.
Plasterboard can take 32kg per metre squared, also prime.
Would it be possible to over board the skimwd walls with some mechanically fixed backer board or at worst plasterboard?
The waiver wouldn't be worth the paper it's written on here, fundamentally you are responsible because you know you should not be tiling on a substrate that can't take the weight. You'd loose in court.

Thanks for your reply. This could be one method as it is just at a shell stage. Or they might have to reboard the original. As the waiver is useless i wont be tiling it until its right.

In regards to the primer, im using the tilemaster prime, as i like to use all the same product. I never used wood glue.

 

[Andy Allen]

Have you checked the weight of the tiles.
I've had some come in on weight or just a tad over which wouldn't concern me to much.

 

[Rickm34]

Have you checked the weight of the tiles.
I've had some come in on weight or just a tad over which wouldn't concern me to much.

Hi there. Checked the boxes no weight or name as such. Just numbers. Nothing in kgs. They are 10mm thick and 'hard'

 

[Andy Allen]

Hi there. Checked the boxes no weight or name as such. Just numbers. Nothing in kgs. They are 10mm thick and 'hard'

Could you not check with the suppliers?

 

[Rickm34]

Could you not check with the suppliers?

Yeah will do that. cheers

 

[Old Mod]

The tiles will weigh approx 24kg per m2
Adhesive has an average weight of 1.5-2kg per mm per m2
As a 10mm trowel will give approximately a 3mm solid bed, this equates to somewhere between 4.5-6kg per m2 depending adhesive.
So you would be looking at a combined weight of approximately 28.5 - 30kg per m2.
This is for guidance only, but should be somewhere near the mark.

 

[Rickm34]

The tiles will weigh approx 24kg per m2
Adhesive has an average weight of 1.5-2kg per mm per m2
As a 10mm trowel will give approximately a 3mm solid bed, this equates to somewhere between 4.5-6kg per m2 depending adhesive.
So you would be looking at a combined weight of approximately 28.5 - 30kg per m2.
This is for guidance only, but should be somewhere near the mark.

Ok cheers i will bare that in mind. Might just take the bathroom scales lol

 

[Old Mod]

Haha you could do worse mate!

In fact I'd be interested to know just how accurate those figures are.

And if they're way off,
Don't post it, send a pm! Haha
Couldn't stand the embarrassment! Haha

 

[Rickm34]

Well if i weighed a box. Then one individually, i could find out.

 

[Old Mod]

Well if u weighed a box and divided it by the number of tiles you could save yourself the effort of opening the box! Haha

 

[Rickm34]

Yeah. But in order to trust the scales you need both numbers. Haha!

 

[Rickm34]

I can see the look on the builders face when the first thing i carry in is a set of scales. He'll think im a right one

 

[Old Mod]

Haha and he'd probably be right!