Substrates for travertine

[_Adrian]

Hi,

I've been reading through the masses of useful info available here, but now could do with some advice please.

I will be tiling a bathroom in 12mm thick travertine, and have only now become aware of the maximum weights supported by different substrates. Wish I'd looked into it sooner

From what I've seen here, the travertine will weigh around 36kg/m2 (including a 3mm adhesive bed), plus grout at 2kg/m2, but the substrates I have and the weights they'll support are:
aquapanel 55kg/m2 (I assumed it falls into the cement backer board category),
sand and cement render 40kg/m2,
15mm plasterboard 32kg/m2 (or is that rating for 12.5mm plasterboard?), and
12mm WBP 30kg/m2.

The numbers look like I'm going to have problems as the WBP and PB won't support the weight... or will it be OK? Maybe its wishful thinking that the numbers are over-engineered.

I was wondering what you guys would recommend as a cost-effective way to overcome this.

Thanks,

Adrian

[Bri]

Hey up Adrian, are all these different substrates walls?

[_Adrian]

Yes, sorry, should have said!

[hillhead]

Hello again Adrian, mixed bag there!
Did I see you have wpb in there on your Walls?

[_Adrian]

Hello again Adrian, mixed bag there!
Did I see you have wpb in there on your Walls?

Yep, these are all walls. Is WBP a problem?

The floors on the other hand are 18mm ply (over 600mm centre joists), with warm water UFH beneath. I was planning to use either plastic ply or Ditra matting over the ply in prep for the same 12mm travertine. Any thoughts?

[whitebeam]

Yep, these are all walls. Is WBP a problem?

The floors on the other hand are 18mm ply (over 600mm centre joists), with warm water UFH beneath. I was planning to use either plastic ply or Ditra matting over the ply in prep for the same 12mm travertine. Any thoughts?

On the walls it could, it's due to the flexibility of ply..

[hillhead]

I certainly wouldn't tile travertine onto plywood walls, that's me.
I have a house in pipe which i don't want to do as there is ply on bathroom walls.
Most ply is chinese and unsuitable for tiling onto unfortunately.
There will be movement no doubt but i'v even seen ply delaminating.
Plasterboard screwed to the studs would have been a much much better option Adrian.

[Rich]

I dont like ply, not good to tile onto at the best of times IMO. Is the ply in a wet area? I would go for a tile backer board given the choice, if cost will not allow then bare plaster board. Both of these want to be mechanically fixed to the wall.

[_Adrian]

Thanks for all the replies guys. The shower and bath areas have the aquapanel, so I'm happy about them.

I'm glad I asked about the WBP! It's not entirely too late as some of it hasn't been fixed. I can use plasterboard instead of most of it, and the one wall where it'll be too much hassle to remove the WBP I can easily overboard with plasterboard - I have some left over 12.5mm fireproof plasterboard that's the right size - is there any reason why I can't use that?

But then this comes back to my first concern about whether the weight of the 12mm travertine is too heavy for successfully tiling onto bare plasterboard?

[hillhead]

If the plasterboard is screwed to the studs Adrian I'd be confident the travertine will be ok.
The overall weight might be slightly over but within reason per m2.

[_Adrian]

Lightning reply! Thanks for that. I'll give it a go.