Porcelain wall tiles onto Exterior Ply??

[sludd]

Hi Guys

I'm refitting my en-suite and have ripped out the existing plasterboard in the shower cubicle. The tiles I am using are 400x400 porcelain and I wonder about using exterior grade plywood instead of plasterboard. The reasons are in case I need to change the tiles in the future without the wall disintegrating and also to get a solid fix into the stud, given the weight of the tiles...

My question is whether this is likely to be OK and will the tiles adhere to exterior ply (as they do on a floor) - if so, what adhesive is best and should I prepare the plywood in any way beforehand.

If not, is standard "green" plasterboard OK and again, what prep (is tanking still required or should I use a primer) and adhesive is best.

I've had lots of experience of porcelain floor tiling without any issues, but not yet on walls...

[Alan.P]

Use plasterboard or backerboards, not plywood, use normal plasterboard and tank it for piece of mind.

[Stewart]

I wouldn't use ply on the Walls. As above, I would use a backer board or plasterboard and tank.

[kilty55]

as above plasterboard tanked would be better

[Gall.B]

Hi Sludd if you want to go the ply road would be stronger but I would go bor marine rather than exterior bonded both sides coverd in screws NOT NAILS, tanked, Adhesive the new bal single part flexible or anything that rubberises also expensive.

Hope this helps m8

[jwatson]

use a tile backing board no issues on weight, strong doesnt let water soak through, it is inflexable, and the tiles will go on beatuifaully. leave 2mm gap between boards fill gap with silicone, scrim joints and adhesive over silicone. good to go.

hope this helps.

[sludd]

Thanks everyone - question answered. No plywood!!

Is there any benefit in the waterproof plasterboard available at B&Q, or if I'm going to tank it does it matter. Alternatively, could any of you guys ( I notice your locations) recommend a stockist of aquapanel or the like local enough to deliver to Cumbernauld.

I'd rather get it right than do it cheap...

[jwatson]

what pattern are you doing with the large format porcelain. brick ect?

[garythetiler]

I saw the g-tec aqua boards in Build Base today and it looks really good, not sure what it costs but the boards look like they would be as easy to fit as plasterboard

[sludd]

Just a standard grid pattern really...

[aph257]

i use standard 12.5mm plasterboard and tanked.

[whitebeam]

Hardie dos'nt break down if it gets wet, it's not water proof.

[Gall.B]

cosmo ceramics dixon blazes glasgow do wedi board pm me and i can give you my 3rd off discount

[paul78]

wickes stock aquapanel.

[sludd]

Is the aquapanel available at Wickes OK - though I suppose builders merchants should also stock...

[Gall.B]

Thanks everyone - question answered. No plywood!!

Is there any benefit in the waterproof plasterboard available at B&Q, or if I'm going to tank it does it matter. Alternatively, could any of you guys ( I notice your locations) recommend a stockist of aquapanel or the like local enough to deliver to Cumbernauld.

I'd rather get it right than do it cheap...

Cosmo ceramics glasgow stock eveything you need p.m. for a third off

[Dave]

Be careful if using ply.. you can only hang 25kg to it..

[ozboz]

You can go with ply mate, use keraquick with latex plus and flexi grout, make sure you spread back of tiles as well as troweling walls, just done a load of this 600x600, no probs at all, ok mate Steve

[whitebeam]

Can't believe ply is still being used as a backing, there is other far better materials for the job available today.

[Scott]

You can go with ply mate, use keraquick with latex plus and flexi grout, make sure you spread back of tiles as well as troweling walls, just done a load of this 600x600, no probs at all, ok mate Steve

An expensive way to do it though!

[sludd]

Decided to go with Aquapanel as a backer.

Does this need to be primed before tiling? I'm planning to use the Mapei porcelain tile cement (from B&Q) for both the walls onto aquapanel and on the floor, onto exterior plywood overboards. (Tiles are 400x400 porcelain)

Do either/both substrates need primed and if so what should I use

[grumpygrouter]

aquapanel doesn't need priming. If the floor is solid, just overboard it with 6mm hardie. Much more stable than ply. If you have movement in the floor on the other hand then you will need to strengthen it first.

[aph257]

I don't know why people still use ply either.

[ozboz]

No reasons not to use ply, providing the correct premium quality board and methods of securing it are followed, Mapiei and the structural engineer had no issues providing me with a spec for my last comtract, so if they are comfident in the use of ply i can see no reason to look beyond the use of this material as and when the need arises, I have used ply for going on 35 years, never had a call back, failure anything, walls , floors whatever,

[Scott]

But if you have the option of an alternative.....

[sludd]

Given that I'm now committed to Aquapanel - what is the best way to cut it (and with what tool), both when cutting along the full length, but particularly to make a hole for the shower valve?

[ozboz]

I am of the opinion 'if its not broke, don't fix it ', should the need arise to go with another substrate then I would , when I reached the shores of Australia over 20 years ago the Aussie's to my opinion made us look as though we were in the dark ages as far as tiling went, materials, power tools the lot. They had boards then similar to the ones that are being talked about now here,and I used them , no problem, but as I remember the this thread began by Sludd was a query about ply, I gave an answer,I have no problem with this method of fixing, Mapei has no problem, as far as the correct installation methods are used.

[Scott]

Funny i thought a forum was a place for discussion.

There are plenty of people who tile to ply, im one of them but only on floors. Its already been stated about the weight issues with ply. With the really poor quality far eastern ply that seems to delaminate very easily and is so light you can lift a sheet of 18mm with one hand. This isnt the same as the ply that we used to find in our timber merchants now everything is down to tight margins and high fuel prices the quality is very poor. Also a sheet of good quality 18mm marine ply will set you back in excess of £50 for an 8x4. Making backer boards a better waterresistant choice.

On that basis i wouldnt advising someone to tile to ply where they may go and buy a cheap sheet from a diy shed and it fail.

[aph257]

i'm of the opinion to keep up to date with technologies. so in regard to "if it's not broke, don't fixit" doesn't always apply. for example: Are you still riding around on a horse and cart? No, Horses wern't broke at the time when cars/vans were invented they were just less efficient, and sand/cement still works but modern addy's are so much better.

[ozboz]

A Company I sub to have recently run into mega problems, still owed around 350.000 by a multi national retail firm , all because the tiling mob they used to do the work succumbed to the call of new technology, ie, 'modern addy ' , had they applied the 'not broke dont fix' mind set,maybe a lot of grief would have been averted. The method that should have been implemented I observed in ancient buildings in Rome ?, amazing. I did a sandstone job, fixed 400 X 400 bedded in s&c to a line, one by one, a load of greek fixers used the same stone, fixed it with adhesive, same conditions, same builder, same everything on a property about 1/2 a mile away , they scoffed at the old timer labouring away down the road, two months later they were back replacing about 70% of their project, very efficient,so much better these modern adhesives ?, yes modern 'addy' does have its benifits, but it also has limitations and is not the be and end all of the tiling trade. I have witnessed so many failures over the last 35 years due to 'modern technology', wonder adhesives,some have been massive failures that have sent companies into bankruptcy , from the manufacture of tiles, adhesives etc ,and recently, now de coupling membranes have come under the hammer , had some of the slower out dated methods been applied the failures more than likely would have been eliminated. Similar projects done the old way are still there as testimony to the time tested methods. It could be said that the problems lie with the fixing. very true in some cases, but not always, so to be honest, I look at each project, and the best way to eliminate potential problems, if there is no modern equivelant way to complete the job , take the 'old ' way, so Im of a mind that if its not broke dont fix it, if alternative means taking a step backwards, then so be it.