Hardie Fixing Or Options

[outcycling]

Hi Guys,
My latest job I am back to brick/blockwork (again) due to weight of tiles and poor render/plaster. Now on a number of jobs I have used Hardie in the shower areas and MR plasterboard everywhere else. Using advice from the tile suppliers I actually D&D'd the Hardie to the walls on a couple of jobs but also mechanical fixed with a lot of fixings. I now just found out that you should NOT D&D hardie :-( but use adhesive with 6mm notched trowel. Using a 6mm notched on the walls Ive seen seems pretty damn optimistic to a) give you a flat surface b) for the adhesive to actually hit the wall in most places. So given that you don't have a pan smooth masonry surface (every job Ive come across!) what do people do ? I could just D&D MR plasterboard and tank it in the shower area but it just feels so weak the surface for tiling on compared to Hardie especially foe heavy tiles.
BTW - current job is Marble 300x400 tiles and about 28kgs pm2.

Thanks for advice.

 

[J Sid]

http://www.jameshardie.co.uk/images...ent_backerboard_installation_guide_manual.pdf
Page 9

 

[outcycling]

http://www.jameshardie.co.uk/images...ent_backerboard_installation_guide_manual.pdf
Page 9
View attachment 78984

Yep, I've seen that julian. Thanks. But that still relies on a pretty straight wall or a hell of a lot of gripfill ! Has anyone tried gyproc H tilebacker ? Was just checking it out online. I remember looking before at this stuff but despit Travis Perkins being a supposed stockist they didn't have any or new anything about it.

 

[mma]

No more ply

 

[Dave]

http://www.jameshardie.co.uk/images...ent_backerboard_installation_guide_manual.pdf
Page 9
View attachment 78984

They must have changed the spec....
It used to be adhesive ribbed onto the walls.

 

[Chalker]

Can't see what the problem is with dot and dabbing the board to the wall. As long as it's mechanically fixed well, the adhesive is just to take up the unevenness.

 

[outcycling]

No more ply

Interesting mma, thanks.

 

[outcycling]

Can't see what the problem is with dot and dabbing the board to the wall. As long as it's mechanically fixed well, the adhesive is just to take up the unevenness.

You'd think unless they are implying that the adhesion is required for holding strength as well ?

 

[outcycling]

Can't see what the problem is with dot and dabbing the board to the wall. As long as it's mechanically fixed well, the adhesive is just to take up the unevenness.

Looks like you were right chalker. I contacted James Hardie Europe direct and got this reply:

"I'd be scared to trust No More Plys claims of 65kg/m2 on a dot'and'dab method.

With us you may use either one, the adhesive on the back of the board is simply meant to be used as a gap filler, Gripfil or cartridge based adhesive is ofcourse easier and faster on straight blockwork walls however we do understand many jobs using HardieBacker are on refurbs. For us as long as you mechanically fix it you may use the tile adhesive or gripfill."

So tbh I can't see why one couldn't use standard plasterboard adhesive either tbh as it is only a gap filler and the fixings are what is relied on to hold it all in place. Unfortunately his reply came back to late and I'd already gone and bought no more ply so will see how it performs on this job compared to Hardie. Certainly seems lighter !

 

[Perry]

As you have to tank the hardie so you might as well use the plasterboard ali-round.

 

[One Day]

Other than 6mm HB for the occasional floor over-lay, why-oh-why-oh-why is anyone bothering with crazy heavy, hard-to-cut, silica-containing, and not to forget: NOT WATERPROOF cement boards anyway?!

Look at these nice, light, easy to use, waterproof boards: "Ooooooooh!"
wedi building board systems – Simply indispensible under tiles – wedi.de
Tile Backer Board | Schlüter-KERDI-BOARD | Schlüter

And please don't say "too 'spensive"
Consider the time saved = increased profits.

There really is no excuse to use HB on walls anymore.