Aquaboard or marine ply?

[lee666]

Hi all, need some assistance on which of the above would be best for my needs.

Basically i'm replacing our victorian style standalone bath with a normal one so we can have a shower. Our bathroom is in a single skin extension and I need to tile 2 walls. I've been looking at the aquaboard, but as the shower will only be used by me and my OH I didn't know if this would be overkill for 10 minutes or so shower time each day. I'm also slightly concerned I might not be able to secure it into the studs, and don't know if they would be too heavy to fix directly into plasterboard.

This leads me onto marine ply. I've been looking at 2400 x 1200 x 6mm sheets, as 2 of these would do both sides I need to do. I'd obviously seal it with PVA and use proper waterproof adhesive.

Would really welcome some advice on this

Thanks

 

[mypetearthling]

Use a backer board.

It may seem like overkill now but it it will be worth it in the long run. Some tilers say it is possible to use plasterboard with a tanking system, but I wouldn't recommend it! The only tile backing guaranteed to be dimensionally stable in a wet area is aquaboard, hardie backer etc as they don't budge, even when soaked.

And whatever you do, don't put PVA near it! It is water soluble and will lead to more headaches than its worth. If you need to prime anything before you tile it only use an acrylic based primer. Preferably the one made by the manufacturer of the adhesive.

Good luck

K

 

[lee666]

cheers for the headsup about pva.

I'm not thinking of tiling straight onto the walls, I would prefer a better surface for the tiles to go on. We were looking at the splashwalls but at £260 for 2 it just seems steep, and once you factor in the adhesive for them and the corner bits i'm sure you're knocking on £300 to do less than 7sq m

 

[lee666]

been looking at the hardibacker, would i need the 6mm or the 12mm for the walls?

 

[mypetearthling]

I'm not sure about the Hardie backer ( I have an inherent distrust of Topps Tiles ) but No More Ply only recommend the 6mm for overboarding cracked concrete floors, so I'd say 12mm would be best. Also that'll make it the same thickness as plasterboard if you choose to use that outside of the wet areas.

The splashwalls stuff is a good idea, but it costs way more than it's worth, and tiles always look higher quality, and give more choice.

Hope that's of some use

K

 

[lee666]

the walls in the bathroom already have painted platerboard on, so would i need 6mm or still 12mm? I presume going by the instructions for no mor eply that I would use the same instructions for a solid wall as opposed to a stud wall, seeing as i already have the plasterboard in place?

 

[Richard C]

Oh my god , do not use ply; use a decent waterproof tile backer board not NMP; only use 12mm on walls; do not use standard PVA especially in a wet area, it won’t seal anything & your tiles will most likely fall on the floor, if you need a primer/sealer use either acrylic or SBR based; do not use plasterboard (& that includes Aquaboard) in a wet area unless you tank it. If your tiling a floor there are special considerations to make if you want it to last.

Before you do anything else, read the Tiling Forum sticky & archive posts to prevent you making basic & costly mistakes. First big question, what size & type of tiles are you planning to hang? We’ll take it from there

 

[lee666]

tile size is probably going to be 33 x 25cm and ceramic ones, so nothing too heavy. The floor isn't being done, just the wall that will be behind the showerhead and the wall to the side.

Was also looking at marmox as well, if that's any good? The total area to be done is just over 6sq m, and that's if i tile from floor to ceiling on both walls.

Cheers

 

[Richard C]

Marmox board is a top quality backer board &, correctly fitted, you won’t have any problems with that. I mostly use Aqapanel which will do the job just as well & is somewhat cheaper; you can direct fix by using dot & dab adhesive & mechanically through fixing the next day after the adhesive has set. Tile weight won’t be a problem for either board but use flexible powder cement adhesive on that size tile or they may move around while your trying to fix & you could wait days for tub mix adhesive to set.

Use only quality trade adhesive & grout products of the correct type for your tiles & tile base, the cheap DIY stuff is generally crap.

 

[lee666]

cheers richard. I won't need to seal the marmox with a primer will i? I was looking at the instructions on how to fit it and it says to screw at 30cm intervals, however i think the gap between joists in my wall are slightly bigger than that, do you envisage any problems if i were to use adhesive then screw at 40-50cm intervals into the joists?

 

[Richard C]

Only prime if the adhesive or tile manufacture recommends it & tile base or other factors warrant it; mostly you won’t need to.

The addition of adhesive won’t really do much, I usually fix to solid walls on a 25cm grid. What are “joists”, you find those in ceilings? Is this studs in a partition wall @ 45-50cm crs? If so I would pitch screws at 15-20cm vertically on the studs (standard for fixing PB) & add some intermediate noggins if there is only one in the centre at the moment.

 

[lee666]

yeah, i meant studs. I may adhesive and screw just for piece of mind. Whats the best method for sealing the corner where both walls meet?

 

[Richard C]

After you’ve boarded out, stick some GRP (plasterboard) reinforcing tape down the corner & along each board joint & smear with tile adhesive just before tiling; work it well into the mesh. When tiling, avoid the tile grout lines coinciding with the boards joints as far as is practicable.

After you’ve tiled, don’t use grout where the two walls meet, it will crack due to differential expansion. Run a bead of silicone down the corner to match the grout colour; you should always do this where two wall meet in wet areas regardless of what they are made of.

 

[lee666]

thanks richard, thought it might be a question of using the tape and sealant. Will start pricing it up now

 

[lee666]

one last question if that's ok? Been looking online for marmox suppliers and some seem to sell 12.5mm thickness and others 10mm. Would there be any problems if i were to opt for the 10mm thick?