Small piece of Hardie backer ok straight onto plastered wall?

[Joe Fixit]

Hi,

Installation manual says to apply 6mm Hardie backer onto plaster, it's best to find where the studs are.

I'm doing a shower niche which is built between the studs. I was thinking of putting. A small piece (370mmx310mm) of Hardie backer straight onto the plasterboard. As it's a bedroom on the other side, I was thinking of glueing and using small depth screws.

Anyone know if this will be acceptable please?

 

[drives]

Not 100% following what you mean but generally 12mm hardiebacker is used for walls and you'd just remove the plasterboard and replace it with the hardie. I have used 6mm hardie before to get the shower niche the right dimensions that I needed and just used extra noggins and halved the spacing between centres (versus the 12mm). Always screwed into the studs/noggins with hardiebacker wall screws.

If it is a bedroom on the other side it might be worth using rockwool sound insulation between the studs whilst you have it all open.

 

[Joe Fixit]

Not 100% following what you mean but generally 12mm hardiebacker is used for walls and you'd just remove the plasterboard and replace it with the hardie. I have used 6mm hardie before to get the shower niche the right dimensions that I needed and just used extra noggins and halved the spacing between centres (versus the 12mm). Always screwed into the studs/noggins with hardiebacker wall screws.

If it is a bedroom on the other side it might be worth using rockwool sound insulation between the studs whilst you have it all open.

Yes I've added rock wool insulation today. The gap you see is where I was planning my niche but as you see, the back of the niche will just be a plastered wall with no studs to screw in to.

I was wondering if I could get away with using 6mm Hardie backer just for the back wall of the niche and just use glue (and maybe small depth screws - small enough not to puncture through to the bedroom side)

 

[Madrab]

Sorry but I'm a bit confused too, all I can see is plenty of studs everywhere to screw into and no discernible gaps?

 

[Joe Fixit]

Sorry, probably me describing it badly.

Iam referring to where the back wall of the shower niche will be. And how I would attach a small piece of Hardie backer to the back there.

As it's just plaster wall (bedroom wall), I don't really want to screw onto it.

The other alternative I thought was to simply tank the plaster wall and tile directly onto it. But was preferring to put a 6mm Hardie backer to make it a bit more robust.

Hope the sketch explains it a bit more.

 

[Madrab]

Ah right, no need for hardie IMO, as it'll be a shower then tank the whole space, including the niche, makes sure there's a complete waterproof membrane and a seal created before tiling.

If you do want to use a piece of hardie then use a piece the exact size of the space then any good quality hi grab adhesive. No need for screws IMO

 

[Joe Fixit]

Ah right, no need for hardie IMO, as it'll be a shower then tank the whole space, including the niche, makes sure there's a complete waterproof membrane and a seal created before tiling.

If you do want to use a piece of hardie then use a piece the exact size of the space then any good quality hi grab adhesive. No need for screws IMO

Thanks. Yes whole shower area will be Hardie backered and got mapei tanking kit.

Might just glue it on as I don't fully trust just having a plasterboard support a tile especially as it's a kids bedroom on the other side (factoring in potentially bumps and acrobats etc.)

 

[Madrab]

Might just glue it on as I don't fully trust just having a plasterboard support a tile especially as it's a kids bedroom on the other side (factoring in potentially bumps and acrobats etc.)

On that size the plasterboard, even 9.5mm would hold a tile without issue but whatever gives you the greater confidence

 

[Joe Fixit]

On that size the plasterboard, even 9.5mm would hold a tile without issue but whatever gives you the greater confidence

Thanks. Slowly convincing me not to bother with Hardie backer. Niche would be that little bit deeper as well.

Ots also the waterproofing. I know hardiebackers not water proof but to me seem a more resistant than plasterboard

 

[Madrab]

I know hardiebackers not water proof

Actually it supposedly is, it's one of their selling points.

As long as the niche is fully tanked and well coated though and then properly tiled with good quality water resistant adhesive and waterproof grout then it should end up fully waterproof.