Advice required - preparing and tanking walls for tiling

[llama]

I'm in the process of building a wetroom - It's a very slow process that i've been in for about 18 months now!

Anyway, I need to build out a wall slightly to hide pipework and a built-in shower valve. For this I was intending on screwing 2x1 battens to the block wall and then fixing my boards to the battens.

With regard to the boards I really don't know whether to use standard plasterboard or aquapanel. I've read a number of posts on this forum and I have the impression that aquapanel is the stuff to use. However, I don't understand how it's better than plasterboard as surely once they are both tanked they would perform the same. Can anyone shed some light as to why aquapanel is so revered?

Also, the other walls in the room have a coat of bonding plaster on them. Does anyone know of a tanking solution that can go straight on the bonding coat or should this be skimed or overboarded with pb or aquapanel prior to tiling?

Your thoughts greatly appreciated.

 

[Richard C]

I need to build out a wall slightly to hide pipework and a built-in shower valve. For this I was intending on screwing 2x1 battens to the block wall and then fixing my boards to the battens.

Which way around are you fixing the battens? 1” width is too narrow for the joints when boarding.

With regard to the boards I really don't know whether to use standard plasterboard or aquapanel. I've read a number of posts on this forum and I have the impression that aquapanel is the stuff to use.

Wet rooms are even more demanding the bath/shower rooms;

Aquapanel – no need to tank if it gets wet, it doesn’t disintegrate

Moisture resistant plasterboard – needs tanking (despite what some will say), has some resistance to water but will eventually disintegrate

Ordinary wall board – must be tanked, has the water resistance of Wheatabix & will disintegrate very quickly if it gets wet.

Can anyone shed some light as to why aquapanel is so revered?

Its cement based, is water proof, dimensionally stable, tough & conforms to building regulations sound insulation requirement on stud walls. Having seen the mess that was once plasterboard lying behind the stripped tiles in many showers, I would never use it in a wet area out of choice. There are many ways to skin a cat & a few other backer boards but, like many, I tend to stick with what I know will work.

However, I don't understand how it's better than plasterboard as surely once they are both tanked they would perform the same.

In a perfect world if the tanking is done properly & it's never breached, yes they will but get a little problem & were back to what happens to the tile base if it gets wet.

Also, the other walls in the room have a coat of bonding plaster on them. Does anyone know of a tanking solution that can go straight on the bonding coat or should this be skimed or overboarded with pb or aquapanel prior to tiling?

Not tried tanking directly over Bonding but can find nothing specific in the spec. that says not to. The problem is that Bonding is rather soft & unless it’s the odd patch here & there, I always finish skim the entire wall & go from there.

Only use quality trade adhesive & grout of the correct type.

 

[llama]

Thank you for you thorough response Richard C. I'll be fitting the 2" face of the battens to the wall and thus fitting the boards to the other 2" face. The pipework and shower valve are partly recessed into the wall so I'm only looking to build the wall out an 1". Incidentally would it be acceptable to use untreated timber for the battens (I already have plenty of this in the shed) or should I buy some treated 2x1?

I will definitely use aquapanel on the battens. I'm actually considering overboarding the bonding with aquapanel as the bonding isn't particularly flat. Plastering isn't one of my skills. I could probably overcome the undulations with tile adhesive but its more mucking around. It seems from reading other posts that I can fix the boards directly to the wall using frame fixings or dry wall screws and wall plugs. I'm hoping this would give an ideal surface to tile.

Giving that this will be a wet room (one day) can you recommend a tanking solution for the aquapanel? I have already opted for Tilesafe on the floor as I'm using an Impey Aquadec and Devimat heated floor.

Thanks once again.

 

[Richard C]

Incidentally would it be acceptable to use untreated timber for the battens (I already have plenty of this in the shed) or should I buy some treated 2x1?

If you have to buy, just as well get treated but it doesn’t matter; hopefully it will never be tested.

Plastering isn't one of my skills. I could probably overcome the undulations with tile adhesive but its more mucking around.

Tile adhesive can be used to take care of the odd bit but you should get the base as flat as possible particularly if you’re going to use large tiles.

It seems from reading other posts that I can fix the boards directly to the wall using frame fixings or dry wall screws and wall plugs. I'm hoping this would give an ideal surface to tile.

Dot & dab the panels to the wall & take a note of where the adhesive is; once the adhesive has gone hard drill through the panel, adhesive & into the wall & fix using through (frame) fixings not screws & plugs.

Giving that this will be a wet room (one day) can you recommend a tanking solution for the aquapanel? I have already opted for Tilesafe on the floor as I'm using an Impey Aquadec and Devimat heated floor.

You can tank Aquapanel with BAL WP1 but I would say it’s not really necessary even on walls in a wet area; but I wouldn’t use Aquapanel on the floor.

 

[jefoss]

id actually like to see a llama do some tiling. can you put it on youtube?

 

[llama]

jeffos, llamas are ok at tiling it's the plastering they can't do! Once I get that far I'll post a vid on llamatube.com

Hi Richard C, once again thank you for taking the time to respond. It's greatly appreciated. I realise the frame fixings should only go where the adhesive is but can I ask how many fixings you would suggest using in a 1200x900 sheet of aquapanel. I was thinking of dabbing the tile adhesive on at approximately 40cm centres. What do you think?

 

[Richard C]

I was thinking of dabbing the tile adhesive on at approximately 40cm centres. What do you think?

40cm is too wide; dabs every 15cm & drill through every other one for through fixings at 30cm x 30cm centres approx.

 

[llama]

Thanks Richard, 30cms it is then. Aquapanel boards are ordered now, just got to get my frame fixings and adhesive. Do you have a recommendation for an adhesive and what length frame fixings would you suggest, 80mm? Thanks again.

 

[Richard C]

I use this;
http://www.british-gypsum.com/produ...roc_accessories/gyproc_dri-wall_adhesive.aspx

60mm fixings should be sufficient but depends what you can get hold of or if you feel more comfortable with 80mmm, use those.

 

[llama]

Righto Richard C, I'll get some of that. Thanks for all the helpful replies. I realise that the adhesive needs to set and that it will depend on the the thickness but in your experience how soon after sticking the panels up will I be able to drill for the frame fixings. Is it a matter of hours or is it a next day job?

PS. I think that's it with the questions now. Thank you for taking the time to respond, your input has been greatly appreciated.

 

[diydoughnut]

Sorry if I'm a bit late getting to this -only just joined in the forum - but we're also doing a wet room and used hardibacker for the walls where necessary. It's fab stuff, not expensive (we got some from Topp's Tiles in the end) and does the trick superbly!

Hope that helps...