suitable substrate for heavy travertine

[newplumb]

Hi there. I'd appreciate some advice please....

My first time tiling with travertine. The customer is going for 600x400 (12mm thick) tiles. The plasterboard around the shower-bath is to be replaced by aquapanel, so can I just check whether you would recommend that I carry out any surface preparation to the aquapanel before tiling with these tiles.

Around the rest of the bathroom, the tiles are only going to go up to a height of approx 1200mm (i.e. 3 tiles high). The walls are a mix of plasterboard, and solid (brick and plaster). I would also appreciate some advice on the best approach to preparing these walls (I'm guessing Im going to need to replace the plasterboard!).

Finally, if you could recommend the most suitable adhesive for the above mix of surfaces I'd be most grateful.

Thanks in advance
Matt

[LM Ceramics]

plasterboard would be suitable substrate but dont skim over the plasterboard thats when the weight issues will come in i would use normal single part flexi BAL depends which brand you use and prime the plasterboard with a suitable primer NOT PVA

[wetdec]

As said plasterboard be cool then put a tanking membrane over it before you tile the wet area.............

..

[newplumb]

Thanks both,

That's very encouraging regarding the plasterboard - I've used BAL spf along with the BAL prime APD on plasterboard before, just not with this size/weight of tile.

So for the aquapanel (there's not going to be any plasterboard in the wet area), no additional prep required - is that right?

Thanks

[grumpygrouter]

No other prep required for the aquapanel but you might want to seal the joints unless you are going over with a tanking membrane.

[newplumb]

that's great, thanks

[beanz]

No other prep required for the aquapanel but you might want to seal the joints unless you are going over with a tanking membrane.

What would be best for sealing the joins Grumps? Silicon do?

[Brindle]

Is it not the general case that plaster weight must not exceed 20kg m2, and plaster board 32kg? Or is that just the theory?
I hope in practice more weight can be hung cos I have one this week!!

[grumpygrouter]

Is it not the general case that plaster weight must not exceed 20kg m2, and plaster board 32kg? Or is that just the theory?
I hope in practice more weight can be hung cos I have one this week!!

Correct...it is not just theory!! Weight limits are there for safety reasons. Exceed them at your (insured?) peril!

[Brindle]

Yes I am insured
Are there any stats I wonder for 'people injured or killed by tiles falling off wall' - be interesting to know?

[whitebeam]

That tile with addy will be about 38kg m2

[beanz]

Yes I am insured

It'll be worthless if you exceed recommended weights. If something goes wrong, prepare for an expensive lawsuit.

[Dave]

Yes I am insured
Are there any stats I wonder for 'people injured or killed by tiles falling off wall' - be interesting to know?

Why do you wana see stats....???


Amazes me that a tiler wants to over exceed weights...

Just for the sake of extra prep work..

[Brindle]

I just said it would be interesting!
I don't want to exceed the weights, i was playing devils advocate really as the first post indicated the weights were likely to be exceeded, that's all. Then it seemed that others might also exceed the weights - this size trav with adi is more like 43kg.
I don't mind carrying out the extra prep

[anotherTiler]

I have a similar problem. My customer wants a shower area tiled with 600x400x12 travertine tiles. Currently the bathroom walls are drylined with plasterboard and skimmed. Since the tiles are going only around the shower tray which is 1400x900, I have decided to cut out the plasterboard in the corner where the shower will be and replace it with Hardie backerboard which can take the weight of these tiles. The challenge is how to fix the backerboard flush with the plasterboard. The plasterboard is fixed with adhesive and the distance from the brick wall to the face of the p/b is only about 40 mm. According to the Hardie instructions, the backerboard has to be fixed to studs which are usually at least 50 mm deep. If I do that the face of the backerboard will end up about 20 mil above the face of the p/b. I was wondering if I could use 1x2 studs with the wider side against the wall so that the stud plus the backerboard will come within 2-3 mm from the face of the plasterboard. I would appreciate any comments. Thanks.

[Dave]

Hello and welcome...you can dot&dab the hardi 500 on with rapid set adhesive....

[faithhealer]

Can't see it being an issue. I take it they recommend 50mm for the length of screw? As long as you 'over compensate' with extra screws/
Or dot and dab as the man says!

[anotherTiler]

Hello and welcome...you can dot&dab the hardi 500 on with rapid set adhesive....

Thanks for the welcome. That's what I was thinking of doing initially but after consulting the Hardie website, I found out that the backerboard is not suited for dot & dab application. I'm not sure why that is but I don't want to go against the manufacturer's installation instructions.

[Dave]

You can dot & dab no probs with rapid set and some additional fixing into the board through the dabs once dry....

Hardi doesn't have all info on their site that they should really..

[anotherTiler]

You can dot & dab no probs with rapid set and some additional fixing into the board through the dabs once dry....

Hardi doesn't have all info on their site that they should really..

They have a FAQ section where they say that in some situations the backerboard can be fixed directly to the wall in which case "the boards must be fully bedded on a 6mm notched trowel bed of flexible tile adhesive. The wall should then be drilled and plugged and the boards fixed back to the wall with a suitable screw." This will be no good to me as then the surface will be 20 mil recessed.

In the same FAQs they say that the Hardi is not suitable for dot & dab. Dave's idea is probably doable but I will have no cover if I go against the manufacturer's instructions.

FAQs | James Hardie Europe

[Brindle]

Well, today I spoke to my customer this morning and explained my concerns, and gave him the solution which he was fine with. So armed with 10 sheets of Hardie Backer, off we went.
Fixed as per Hardie backer point 5 as you say....Walls that were old pinked plasterboard, flexi cementious adi, then boards up, staggered, and drilled into studwork. Some p'board plugs and screws here and there too. Another wall was old masonry and some well stuck on small tiles, same treatment here, only drilled through, plugged and screwed all over. You could hang an elephant of these walls now YAY.

Tiles go on tomorrow....