Shower Room Tanking Advice Please

[SB4U]

Hi Everyone. I'm currently DIYing my en-suite shower room and could do with some advice re tanking.

The floor is a new sand and cement screeded floor with in-screed UFH and an Impey Aquagrade former as the wetroom style 'tray' which needs a tanking membrane on it. The dimensions of the former are 1050x1350. I will be installing some shower screens though, so it won't be a full wetroom as such so was intending on not tanking the floor far beyond the tray itself.

The walls are plastered blockwork, although where I removed the tiles from the old shower cubicle, and a few other places, the plaster skim came off too leaving just the first coat plaster. The walls are surprisingly level though, apart from one which is all over the place.

I'd originally planned on using Impey Tilesafe tanking on the former and part way up the walls, as that was what was recommended by the Aquagrade supplier but we've since decided on large format tiles (300x600x9) and I think the plastered walls, or indeed the Tilesafe, won't take their weight as they'll be over 20kg/m2. So I thought that maybe it would be a good idea to dot and dab plasterboard to the walls (plus through fixings) and tank that. Tilesafe still wouldn't be suitable but Impey also do a product called Waterguard which has a higher load bearing capcity of 30kg/m2 which would do the trick. Plus, an added advantage to installing plasterboard is that it will hopefully make tiling with the large tiles easier for me as the substrate should be more level.

Alternatively, rather than tanking the walls at all, I could possibly use something like Marmox or Wedi in the shower area and just use a tanking membrane on the floor. But I thought as there'd be enough membrane left over after doing the floor I could save a bit of money by using that on the walls over normal plasterboard. This project has already cost a small fortune (and many months of time too!) just to get it to this stage, although you'd never believe it by looking at it, so it would make a nice change to save a bit of money.

Or alternatively I could tank the walls with WP1 and use a cheaper membrane on the floor, like Homelux maybe.

Arrrrggggghhhhh. Too many options!!! What would YOU recommend?

Steve

P.S. I was going to upload some pics but couldn't work out how to do it. Might try again later.

 

[Alan.P]

The time and money as you say you've already put into the room, do the job right, overboard the walls plus mechanical fixings, tank everywhere on the floor and wet areas on the walls, you already know the products so I won't list, whatever takes your fancy.

 

[SB4U]

Thanks for the reply @Alan.P It's good to know I'm on the right track anyway.

I think I might go for just bog standard plasterboard everywhere except for the shower area where I'll use Aquaboard. And then tank the bottom metre of the shower area with Waterguard. Hopefully that'll do it.

 

[Old Mod]

Thanks for the reply @Alan.P It's good to know I'm on the right track anyway.

I think I might go for just bog standard plasterboard everywhere except for the shower area where I'll use Aquaboard. And then tank the bottom metre of the shower area with Waterguard. Hopefully that'll do it.

When u mechanically fix any backer board in a wet area, waterproof or not, u still need to tank the joints (unless u use their board adhesive specifically for joining boards) and fixing points.
Every time u breech the board with fixing points its then not waterproof

One option would be to fix plumb batons to your shower walls, then board with 12mm Hardibacker then just tank it all with Ardex WPC.
It's competively priced tanking system and is very easy to use.

It's already been suggested that after investing so much time and money it would be inadvisable to do something u hope will work.

 

[SB4U]

Thanks for the reply @3_fall What you're saying makes good sense.

I'd prefer not to batten if I can get away with it as it'll take just a bit too much off the dimensions of the room which will then make the wall to wall cabinets we've chosen not fit.

Perhaps I could dot and dab Aquaboard with through fixings and then use the Ardex over the lot anyway.

I'd thought I'd use tile adhesive on all the joint edges throughout with jointing tape over. Or is there something more specific I should use?

Steve

 

[Old Mod]

Thanks for the reply @3_fall What you're saying makes good sense.

I'd prefer not to batten if I can get away with it as it'll take just a bit too much off the dimensions of the room which will then make the wall to wall cabinets we've chosen not fit.

Perhaps I could dot and dab Aquaboard with through fixings and then use the Ardex over the lot anyway.

I'd thought I'd use tile adhesive on all the joint edges throughout with jointing tape over. Or is there something more specific I should use?

Steve

Hey Steve,

With Ardex WPC, it comes with a roll of jointing tape, u apply the tape and then with a thicker mix of the WPC u cover the joints.
Only mix a little at a time tho, it's sets quite quickly and is easily wasted.
The instructions are very simple to follow.

Just try to stagger your joints with the boards.

No u don't need to baton first, it's just easier to plumb the batons rather than the boards, well for me anyway.

Mechanical fixings are a must tho.

Marc.

 

[SB4U]

Thanks Marc. I'll give that a go. Gonna order the boards now.

Steve

 

[Alan.P]

Don't make the common mistake of thinking Aquapanel is waterproof in any way, it still needs to be tanked, it's water impermeable, not water proof / resistant.

 

[SB4U]

Thanks @Alan.P Yeah. Got that. I've just received a sample of Waterguard this morning. Looks good (to my untrained eye anyway). I'm thinking I'll use that on the floor and then there should be enough left over to do a metre up the walls in the shower area. I'll then use the Ardex from the top of the Waterguard to the ceiling, covering the joints and fixing points as what @3_fall was saying earlier.

Don't want to get ahead of myself though. Gotta get the boards attached yet!

Steve

 

[Orbry]

Lots of great advice, obviously everyone here is very experienced with wet rooms. We would recommend the same, waterproof backer boards with joint tape/waterproof compound. Good luck!

 

[SB4U]

Started fitting the plasterboard and aquapanels to the walls at the . Didn't quite manage to finish but there's not much more to do really. I think I did my dots a bit big though so the boards are further away from the wall than I'd imagined. On the plus side I'll save a bit of money on the tiles as I now have a considerably smaller room! I didn't think through what I'd do at the door architrave either. Do you have any hints on the best way to build them out?

Also, what mechanical fixings do you use with the aquapanels? I tried hammer in fixings but they went through the panel! I don't fancy the idea of a panel full of tiles falling off but leaving the fixing in place!

Steve

 

[Impey Showers]

Steve

Waterguard can indeed be used on the walls. We have not finalised full literature yet but our tech team would be more than willing to offer advice on wall application.

 

[Old Mod]

Started fitting the plasterboard and aquapanels to the walls at the . Didn't quite manage to finish but there's not much more to do really. I think I did my dots a bit big though so the boards are further away from the wall than I'd imagined. On the plus side I'll save a bit of money on the tiles as I now have a considerably smaller room! I didn't think through what I'd do at the door architrave either. Do you have any hints on the best way to build them out?

Also, what mechanical fixings do you use with the aquapanels? I tried hammer in fixings but they went through the panel! I don't fancy the idea of a panel full of tiles falling off but leaving the fixing in place!

Steve

U can use Wedi style washers or dowels

 

[SB4U]

U can use Wedi style washers or dowels

Thanks @3_fall I didn't realise they existed. Could I just use normal hammer-in fixings with the washers? And would I need to countersink into the boards to get the heads flat?

 

[Old Mod]

Personally I've never used hammer fixings and tbh I don't know if they're are suitable.
Thinking logically, the way I see it if u use a hammer fixing u could easily drive the fixing straight thro and probably the hammer head with it, but I honestly don't know.
U said yourself u drove the fixing straight thro.
I would always use screw fixings, I feel u have a lot more control over it, and for me they're more secure.
I know screws and washers work because that's how I mechanically fix all my boards.
The washers are pre countersunk
Your architrave u can deal with by putting a small timber fillet under the architrave which is thick enough to bring it out to where u need it to be, then just fill and decorate the timber fillet and architrave joint.
It'll appear to be a thick architrave when you've finished, but only in the door lining.

 

[SB4U]

Thanks for the reply. I suppose I thought the washers would stop the fixings (and my hammer) going through the boards. Almost all the boards are now dot and dabbed into place so it might be difficult to get a rawlplug in the right location. Or would it?

 

[Old Mod]

Like I said, hammer fixings are something I know nothing about I'm afraid, maybe someone else could shed some light on that for you.
All I do is drill, plug and screw to the washers.
I don't understand personally how getting a hammer fixing in the right place is any easier than drilling for the plug.
Maybe u could shed some light on that for me?

 

[SB4U]

My thinking was that there's a gap between the board and the wall so it might be difficult to manoeuvre a plug in. But what I didn't think about was that I'll be going through the dot adhesive anyway of course, so it shouldn't be a problem actually. Thanks again.

And thanks for the advice about the architraves too.

 

[SB4U]

Hi. I should have finished boarding the walls by this weekend and be ready to apply the Waterguard membrane. I must admit that I didn't enjoy working with the Aquapanels. Some of them were a bit warped which made levelling them a bit tricky. Plus I dot and dabbed them one evening with a view to mechanically fixing them the next evening. However, they fell off the wall during the night so, lesson learned there. I also should have marked more accurately where the adhesive dots were to make it easier to decide where to put the fixings.

Should I bother taping the joints of either the plasterboard or aquapanels? The aquapanels will be mostly covered by the Watergaurd tanking membrane as I've got enough to cover the floor and well up the walls in the showering area. Is there anything I need to consider before applying the Waterguard.

Just thinking ahead, do you have any recommendations for a suitable tile adhesive to fix my large tiles to the Waterguard (and the non waterguarded areas of course)?

 

[SB4U]

I've now almost finished tanking the walls of the shower area (pics attached). Just need to apply the butyl beading to the joints. The Waterguard membrane was really easy to apply once I got the hang of it. I found the best way to install it was to stick the top bit on first and then gradually peel off the backing a bit at a time and smooth as you go. Super simple even for me. Annoyingly though I miscalculated what I needed and have ended up 1.8 metres shy of what I need to complete the floor so if anyone's got any offcuts they'd sell me I'd appreciate it rather than buying a whole 5m length. I tried Impey but they haven't got any spare unfortunately.

One other thing I want to check with you is that, as the floor to ceiling height is a bit more than 2400 I've got a gap at the top of the plasterboard that's up to 4cm at the most. Should I try to fill that before I tile or can I just fill it with tile adhesive when I get there do you reckon?

Steve