Shower cubicle plywood and electric

[Paul ( Skiing8 )]

I am in the process of fixing the shower cubicle, had a leak and totally destroyed the plasterboard behind, tiles were falling off, etc. Anyhow, I totally ripped out the shower and will be in the process of re-installing this week. I have a couple of questions.

I am thinking about doing the job properly and using marine ply instead of plain old plasterboard or water resistant plasterboard. Is this what you would do or should I be doing something else? What about alternate products instead of tiling?

The other thing is that when I stripped everthing out I noticed that on the other side of the wall there is a plug socket. the back of the metal back box is visible. Where the shower was leaking was very near it. Is there any regulations on this? should there be some plastic covering it? should I or can I cover it with plastic to make it more safe. Can I build a cover around it? After I fix the shower the likelyhood of water ever reaching the socket is going to be very minimal but while I have access to it I might as well make it right. What can you suggest?

[Brianb]

Look at a product called Aquaboard, I saw it in my local tile shop. It's water proof and can tile straight on to it, which you can't with ply.

[Dave Plowman (News)]

Nothing will survive a leak in the wrong place - like behind the cladding. Tiling on plasterboard is perfectly ok provided it gets the chance to dry out properly after use through decent ventilation. You need a good seal between walls and base, though.

[Grunff]

[Christian McArdle]

Use WBP ply. Proper marine ply is many times as expensive and offers no additional benefit in this application. Some use Aquaboard, which is good, but very expensive.

Be careful when tiling. You should use a top quality tile adhesive. Avoid value adhesives and those claiming suitability as a grout too. I'm sure I could buy a car that can mow lawns, but I suspect buying a separate car and lawnmowers would result in better results for both tasks.

I usually use a tile adhesive that claims suitability for commercial swimming pools. Ardex Flex is my favourite. Hard to find, but worth it. Ensure you fully fill behind the tiles. No dot-n-dab here. Occasionally take a tile off immediately after affixing and ensure that it fully bedded in with no air gaps. If there are any, start again. Use a quality grout, also claiming commercial swimming pool suitability. Finally, seal the grout (and the tiles if porous) with a decent sealant, like Lithofin StainStop KF. With that lot, the tiles will stay affixed for 100 years. The grout will stay clean, too.

For your application, I would recommend:

Ardex-Flex 6001 Adhesive Ardex-Flex FS Grout Lithofin KF StainStop Sealant

After I fix the shower the likelyhood of water ever reaching the socket

If you're worried, cover the back with some left over ply and seal it to the wall with some silicone.

Christian.

[Christian McArdle]

Yes, I forgot to mention in my post that a good coating of dilute PVA is required before tiling when using ply.

Christian.

[Doctor Drivel]

Use Aquapanel available from Wickes. You can cut and drill it and tile directly on it. 100% waterproof.

[Christian McArdle]

Ardicol D20. However, this is a readymix and not quite so heavy duty. To be honest, I'd probably still use 6001, or 7001 TS, although I take no responsibility for the consequences!

[Chris Bacon]

It's better to prime the plywood first, isn't it?

[Grunff]

One coat of dilute PVA, yes - but that's hardly extra work.