Installing a shower

[Giesse]

I'm about to install a shower in my ensuite and I'm trying to find a little information about exactly how it should be done. I have a moulded shower base and I'll be tiling the walls inside the shower. I believe Villaboard is the go for lining the walls behind the tiles, but I'm trying to find some instructions regarding the exact procedure. I have the bottom of the walls recessed so that the wall sheets will overlap the edges but before I go any further I have a few questions.

1 - I've seen reference to installing a waterproof plastic sheet behind the villaboard. Is this necessary and if so, why? Isn't the villaboard waterproof? I've also heard plenty of people tell me to just fasten the sheets straight to the studs and then tile. I'm not sure what's right.

2 - Since the rest of the ensuite will be lined with plasterboard, how do I join the edge of the villaboard to the edge of the plasterboard where one surface meets the other, since plasterboard is 10mm thick and villaboard is only 6mm?

If anyone knows of a link to a site that can answer all of my questions, perhaps with some good diagrams etc, that would be great.

Thanks...

[Shane Watson]

I just finished putting fancy new taps on me sink! So I can help with that! hehe.. ;)

[Sturdee]

I rebuilt my shower a couple of years ago and I was advised to put a waterproof plastic membrane under the shower and coming up on the sides behind the wall linings for about 30 cms.

This was to stop water seeping behind the wall lining if the shower base got blocked and flooded.

I didn't tile it but used special laminated sheets, I presume that your tiles and the villaboard will be about the same thickness as your plasterboard so you should not have any problems with finishing.



Peter.

[journeyman Mick]

First off, there's two different ways the term "waterproof" is used. You have "waterproof" as in the material itself does not disintegrate when subject to water and secondly you have "waterproof" as in an impermeable barrier. Tiles, grout and villaboard are all waterproof in that they won't disintegrate in water, however they will not stop the passage of water, merely hinder it.
If you build a shower recess out of villaboard and tile and grout it water will make its way through the grout joins, through the cement sheeting and into your wall cavity. You need to install a waterproof membrane over your sheeting and behind the tiles and down onto the lip of the tray. I use a product called "Liquid Flash" which is a thick acrylic based paint like material with fibreglass stands in it. There are other brands and types, some of which employ fibreglass matting and a paint like product, however I find the all in one product more convenient. Make sure that you follow the instructions to the letter, especially about the bondbreaker tape in the inside corners.
I sit the shower screen on the edge of the tiling line and would use a stop bead on the edge of the gyprock if I had to use it. I would, however suggest that you use villaboard instead, it's only marginally more but makes a better wet area wall. Just remember that if you are laying tiles on villaboard (rather than hardiflex or versilux) you can't tile over topcote.

Mick

[zymurgy]

Giesse,

Visit the James Hardie site (makers of Villaboard) and you will find lots of info. eg. Bathroom Fixing PDF (http://www.jameshardie.com.au/buildingproducts/brochures_sub.asp?id=10)

Gordon.

[kenmil]

And as Mick has said, you should definitely do all your walls with villaboard, not plasterboard.

[Giesse]

If I shouldn't be using plasterboard, then what is wet-area plasterboard used for? And isn't Villaboard basically just cement sheet? Wouldn't that be rather hard and noisy for use as an internal wall?

[zymurgy]

Giesse,

I don't understand 'hard'.

Villaboard has a tapered edge to allow taping and filling just like plasterboard. It's 6mm thick, add your standard tile and glue and your at same thickness as plasterboard, before you tile.

I used it when I redid the laundry, bathroom and toilet. Bathroom and toilet tiled to ceiling and laundry half way up (SWMBO wanted it that way).

I also replaced floorboards with compressed sheeting, basically followed the Hardie guide.

Gordon.

[Giesse]

Hard, as in not soft. Wouldn't it be like having concrete walls (OK, so not THAT hard...)? I've always considered that cement sheet is something that you line sheds with, not houses. I must admit, though - I haven't seen Villaboard as yet, so I'm only making assumptions about it being as hard as cement sheet. Perhaps it isn't, but that was the impression that I got.

Also, I'm thinking that when you whack your fist on a cement sheet wall it tends to vibrate, whereas plasterboard gives more of a dull thud. Once again, perhaps Villaboard is different.

[journeyman Mick]

If you rap on a villaboard wall it will give off a sharper sound than a plasterboard wall but unless you plan on spending a bit of time rapping on the walls you're not going to know the difference. If you follow the fixing instructions, nails/screws & adhesive, it shouldn't vibrate. A finished villaboard wall will look the same as a finished plasterboard wall but it won't get dings and scratches in it to the same extent as a plasterboard wall. If you hit it hard enough you will get a hole, but the same goes for plasterboard. Yes, villaboard is just cement sheeting, but I bet you don't know what plasterboard is made of. Despite its name plasterboard is not two sheets of paper with plaster in between. The white stuff is actually made mostly of recycled chook poo that's been bound with a bit of plaster! It makes great mulch, especially on heavy clay soils. Wet area plasterboard is slightly more water resistant than the run of the mill stuff but you won't catch me using it.

Mick

[George]

Also have a look at the new Hardies wet area lining product called Ezy-Grid Tilebacker. It looks interesting. It is basically villaboard with a grid scored into it and fixing points marked. It is claimed the grid makes cutting easier and also helps when applying the tile adhesive.

Unless you are just replacing a section, use villaboard right through the room. If you mix and match villa with gyprock you need to pack out the villa to account for the thickness difference. But I can't see any advantage, you would be asking for trouble with gyprock in a bathroom.


George

[Sime]

From what I hear you saying - you are actually renovating the ensuite - not putting in a new one. If this is right thenm I understand why the Gyprock is already there, and your hesitation to pull it all out!

I had the same thing in my bathroom. I cheated by tiling over the joins so the step was not noticeable. Must say though that there really wasn't that much of a step anyway.

Have you thought of tiling to the ceiling all through the ensuite? Is it an option?

Simon

[Giesse]

Well, technically, anything is an option. But it's looking like I'll have to basically remove ALL the existing plasterboard, so perhaps I'll just use Villaboard right through.

I also have had a lot of people telling me that I should be using Lamipanel in the shower recess. Even if I use Villaboard everywhere else, the Lamipanel is only around 3mm thick, so I'll still have a step where it joins the Villaboard. I'd have an even BIGGER one if I used Gyprock. So what do people usually do? I could put a strip of wood over the join, routed on the back to compensate, but is there a better way?

[KevM]

Chris,
The lamipanel goes over the villaboard in the same manner that tiles do. There is not enough thickness in the lamipanel on its own.

regards

Kev

[George]

Are you removing tiles from the existing gyprock? If so you may find that you do a fair bit of damage to the sheeting. Depending on the job (condition of sheeting, type of tile adhesive used previously and age) it can be quicker and easier to re-sheet and then tile on a nice new surface.

If you do replace just a section of gyprock with villaboard, tack strips of 3 mm masonite to the studs where the villaboard will be fixed. This gets the thickness difference to within 1 mm. Tape and base coat the joins and preferably extend the tiles over the join as well. I would keep any gyprock/villaboard joins well away from the shower stall itself.

In terms of waterproofing, have a look here for some basics
http://www.norcros.com.au/diy/howto/waterproof.htm
I have used the ABA Superflex Bathroom and Balcony product, but there must be 100 waterproofing membrane products around. All have slightly different recommendations so read carefully.

Cheers
George

[Giesse]

Firstly, Kev - I had a read on the Laminex website and, according to their instructions, you are supposed to fasten Lamipanel directly to the studs and it even specifically says that you shouldn't put Lamipanel over a cement sheet backing.

George - thanks for the link. I'll have a read...

[journeyman Mick]

I've fitted lamipanel both directly to studs and onto fibro, both work. I'd be hesitant about fitting directly to the studs now as it makes it impossible to fit a full waterproof membrane. The plastic corner moulds are supposedly waterproof but I tend to be very cautious with waterproofing as any leakage can be disastrously expensive to rectify. I need to guarantee my work and a call back would be costly, both in terms of my reputation as well as time and money.

Mick

[Giesse]

So why would Laminex say not to put Lamipanel over fibro? I can't see the reason, myself and as you said, it's better for waterproofing.

[journeyman Mick]

The problem might be with the adhesive laminex manufactures for use with lamipanel. It's similar to liquid nails/maxbond. I don't use these types of adhesives at all anymore as they have a tendency (in the heat up here at any rate) to go hard and let go after a while. I use polyurethane adhesive/sealants like Sikaflex or Bostik Matrix. These are more expensive but are worth the peace of mind. I've fitted heaps of lamipanel over the years to all types of substrates, timber, fibro, blockwork, tiles and lots of aluminium boats and I've never had any problems using the polyurethane.

Mick

[Giesse]

OK... so if you attach Lamipanel over the Villaboard, what spacing would you use for studs/noggins behind the Villaboard? I assume that you wouldn't need as many since the Villaboard would re-enforce everything.

[journeyman Mick]

If you use 6mm sheeting then 600 centres is fine, for 4.5mm sheeting use 450 centres(not sure if villa comes in this, I know that hardiflex does/did).

Mick

[Giesse]

No, I think 6mm is standard.

One more question.... under the shower base - do I need some sort of waterproofing? It's a "synthetic marble" (i.e. standard...) moulded shower base and will be installed on a yellow-tongue floor. I've recessed the bottom plates/studs to take it, and I was thinking of putting a layer of plastic sheet under the concrete bed and up the walls a little... but then I thought that the whole thing could still just slide over the floor since there's nothing to keep the plastic from moving. What's the right way to do it? I've searched the internet everywhere and can't find anything - everyone tells you how to install a custom-built base, but not a moulded one.

[journeyman Mick]

Hmm, you've got me there, I've searched my memory banks and I don't think I've ever fitted a plastic tray. I have however fitted plenty of fibreglass and plastic tubs and "shubs" (all in one shower/small bath enclosures) and I would assume the same applies. I install these on a bed of "compo". This is a stiff concrete mix (usually using fine aggregate or cracker dust). On timber or structafloor I nail down a piece of fibro first then place blobs of compo down and force the shub down. You may have to lift it off and add/subtract compo as required. When you've got it right add just a smidgen more so you get good contact/suction. The compo will hold the item in place as well as providing support. When fitting a tub it's easier as its possible to pack a lot of it in once the tub's in place. Check with the manufacturer of the tray for their recommendations.

Mick

[Giesse]

It's not plastic - the manufacturer calls it "synthetic marble" and it weighs like concrete! It's just a standard shower base - as far as I knew, that's what they were all like. It does look a bit like fibreglass underneath (but without the fibres), but it's smooth as a babies rear end on top and is very heavy.

[journeyman Mick]

Okay, sounds like the "cast resin" they make some vanity tops out of, looks like a cross between fibreglass and concrete. Again check with manufacturer/supplier as to fixing recommendations. If no specific method is suggested, I would recommend using Sikaflex or Bostix Matrix to glue it down to the floor, making sure to prime both surfaces to the adhesive manufacturer's recommendations.

Mick

[Giesse]

They actually tell you to put a 10mm min cement mix underneath it - but I was concerned about the idea of just throwing the cement straight on the wood. The cement sheet underneath sounds like a good idea, though.

[journeyman Mick]

Yeah, I think I'd make it like a stiff mortar, maybe put a bit of lime in it so it sticks real well to both the tray and the fibro on the floor.

Mick