Plasterboard behind shower board or something else?

[RigidRaider]

You'll normally find me over on Plumbing where I get great advice on my bathroom project.

I have an entire stud wall opened up for re-plumbing and wiring for the bathroom, the wall is exactly 2.4m x 2.4m. I plan to finish the job by filling the space between the timbers with insulating slabs then get the plasterer to board but not skim. (The rest of the bathroom will be skimmed to hide the awful finishes we inherited.) Then I will be boarding the entire wall with Mermaid shower board, which I will fix to the wall with blobs of adhesive. I did this for the en-suite shower and it worked fine.

However I am wondering if plasterboard is actually the best thing for this job. We want to get as much soundproofing as possible and there are some bits of plumbing for taps, shower valves etc to come through. I'm also concerned that sticking heavy shower board (it's a dense marine ply laminate) to the paper outer of pasterboard might not be such a brilliant idea.

What other material would you recommend for this?

 

[Richard C]

Are we talking about “wet” areas or just the general walls in a bathroom? I’m not familiar with fitting Mermaid shower board at all but had a quick Google; looks rather expensive, do you prefer it to tiling? Also, how do you provide a waterproof seal between the boards? I never use PB in wet areas if I can avoid it & if I do, I tank it. Re sticking it onto PB, what does the manufacturer recommend; there is a maximum wt/sq metre you can stick onto PB & plastering first reduces this.

All the work I do involves tiling, plastering & installing bath/shower rooms, I always use this in wet areas & tile directly onto it;
http://www.aquapanel.com/index.php?lang=en&page=products

For other areas if you must use PB, use Moisture Resistant & not ordinary wall board but MR needs priming before plastering.

 

[RigidRaider]

Thanks for your reply. Yes, it is expensive but I have used it in the en-suite shower and it's an impressive system. It is a marine ply laminated with a decorative Formica front in a variety of finishes and a stabilising Formica back. It comes 2400mm high in 900 and 1200 mm shower panel and 600 mm wall panel kits, which have engineered joints. It comes with a complete system of beads and a very well designed bottom bead for the shower or bath side, which is claimed to tolerate a 10mm sag. The engineered joints are made with their own sealant and the corner joint has a special V bead. The material itself is very dense and stable and cuts perfectly with a sharp saw.

In the en-suite I just used it against plasterboard and after four years it looks as good as new with no sign of leaks. By now a tiled shower would be mildewed, in my experience.

So yes, after all that it's going to be a wet area as the board will be from ceiling down to a bath with shower screen and then ceiling to floor along to the end of the room, also behind the washbasin. I will mention the Aquapanel you recommend to our plasterer.

 

[Richard C]

In the en-suite I just used it against plasterboard and after four years it looks as good as new with no sign of leaks. By now a tiled shower would be mildewed, in my experience.

I would have to disagree with that; with the correct preparation & tiling carried out using quality trade products of the correct type, a shower or wet room installation should last at least 10 years, up to 20 years or even longer. The biggest cause of problems is DIY &, unfortunately, some “tradesmen” who don’t really understand the materials, have no real idea of what they are doing & trying to do it “on the cheap”; problems & early failure can invariably be traced to poor preparation &/or poor quality & inappropriate materials used.

So yes, after all that it's going to be a wet area as the board will be from ceiling down to a bath with shower screen and then ceiling to floor along to the end of the room, also behind the washbasin.

It wouldn’t be my choice but, hey, if you’ve used it before & are happy with the results then who am I to argue with that.

I will mention the Aquapanel you recommend to our plasterer.

Aquapanel is a waterproof, cement based tile backer board and it’s not intended to be plastered although it can be done with the correct preparation & materials.

 

[RigidRaider]

The little I know about paint formulation tells me that cheap sealants will indeed contain lower amounts of cheaper fungicides and will of course go mouldy sooner.

It helps with our own shower that we're in the habit of drying out the shower cabinet after use. Our bathroom is also well ventilated as the window faces west over open fields and is always open on the latch. I remember when we bought the house, noticing some mildew on the bathroom cornice and thinking "Hmmmm... damp....". Little did we imagine the horrors we would find when we ripped out the old shower and pulled down the ceiling below!

The Aquapanel is an interesting recommendation and no; I wouldn't bother skimming it since it will be hidden.