My 1st Job Hardiebacker confusion

[Dan Fitchie]

Hi, my first post and as the title suggests my first attempt at renovating a bathroom.
I bought some hardiebacker 500 for boarding around the shower area with the intention of using the fixing to masonry instructions given by hardiebacker ie high strength gap fill adhesive and screws into the wall. However after stripping off the old blown plaster and render down to brick have found the brick work to be very uneven, and maybe I'm thinking about it wrong but I can't figure how I'm going to get the boards level before mechanical fixing using just a small amount of gunned adhesive. Does anyone have any ideas?
Thanks

 

[Bond]

You could strap the wall with pre-treated timber battens,e.g. 25 x 50mm. And fix board to that.

or glue -on packing pieces to straighten wall, prior to boarding.

 

[Blunt Tool]

You would be better to prime/stabilise brickwork and get some powder bagged flexible tile adhesive mixed and dot dab boards on plumb and level marking where you have put dabs on outer face of boards so when dry drill screw and mechanical fix thru boards and dabs securing onto brickwork.

 

[Dan Fitchie]

Thanks for the suggestion bond. It's a tight room and the battens would bring the tiles past the door frame on one of the walls. Forgive my ignorance but what do you mean by glue on packing pieces?

 

[Bond]

Thanks for the suggestion bond. It's a tight room and the battens would bring the tiles past the door frame on one of the walls. Forgive my ignorance but what do you mean by glue on packing pieces?

 

[Dan Fitchie]

You would be better to prime/stabilise brickwork and get some powder bagged flexible tile adhesive mixed and dot dab boards on plumb and level marking where you have put dabs on outer face of boards so when dry drill screw and mechanical fix thru boards and dabs securing onto brickwork.

I didn't think you could dot dab hardiebacker? It says not to on their faq or are they referring to solely using dot dab. Is it OK with the additional mechanical fix?

 

[Bond]

Would go with callatiler suggestion.
Packing pieces, of various thickness spaced to straighten wall, then glue and fix through these.

 

[Dumbo]

Take the hardi backer back . Get some wedi / Marmox or jackoboard then dot and Dab and mechinacally fix when dry

 

[Blunt Tool]

Flexi tile adhesive dabs and mechanical fixed boards will be fine but you could have used tile insulation boards ie Wedi, marmox, Kerdi which are lighter easier to cut and more suited for walls. If you can get refund and swap over that’s what I would do. Same installation method only difference is you need a purpose made washer per screw that supplier of boards should have in stock.

 

[One Day]

A shame that you've got hard. It's so readily mis-sold. If you can return it, then do so and get 20mm wedi/marmox/jacko boards instead. These can be easily fixed to uneven brick using dabs of tile adhesive.
If you're stuck with hardi though, I'd fix it with dabs, but you'll need to also use mechanical fixings such as frame fixings.
Please also remember hardi isn't waterproof in a wet area. You'll need to tank it.

 

[Rookery]

I'd dot n dab fresh plasterboard, then tank. Simples.

 

[Dan Fitchie]

Appreciate the responses, I think I'm going to return them. They are from b and q so should be fine.
I'm struggling to find any stockists nearby for marmox, wedi or jacko boards.
I know I can get nomoreply which can be dot and dabbed. If hardiebacker was going to need to be tanked anyway which again I didn't realise, can I just use moisture resistant plasterboard and tank that? Or is it not recommended for shower areas?

 

[Qwerty]

Save your money and use standard square edge plasterboard. If fixed and tanked correctly, you will have no issues

 

[Flintstone]

If space is limited for building out, you might as well stick with the hardie backer dot and dabbed as its 6mm thick and not 20mm like impish suggested. You can actually dot and dab with 12mm thick wedi type board tho.

 

[Dan Fitchie]

The

If space is limited for building out, you might as well stick with the hardie backer dot and dabbed as its 6mm thick and not 20mm like impish suggested. You can actually dot and dab with 12mm thick wedi type board tho.

The hardie I have is the 12mm one not 6mm

 

[Flintstone]

Ahh. I’m not too familiar with the hardie backer ways but no more ply you can dot and dab 6mm. I can’t see why hardie is any different

 

[One Day]

If space is limited for building out, you might as well stick with the hardie backer dot and dabbed as its 6mm thick and not 20mm like impish suggested. You can actually dot and dab with 12mm thick wedi type board tho.

20mm for spotting on walls. If you use thinner, there's zero come-back. Wedi, Delta, Jackon - all say 20mm
https://www.wedi.de/fileadmin/media...Building_boards_-_interior_GB_2015_SCREEN.pdf
(page 16)
As for 6mm cement board on walls... not for me thank you!

 

[Flintstone]

Not for me either. It’s the lowest build up way tho if he is tight for room.

My mistake, I’ve been overboarding a lot of stud work with 12mm boards recently. Although tilefix, where I get some stuff from suggest you can use 12mm dot and dab

Dry Lining With Marmox Multiboard - https://www.tilefixdirect.com/blog/2015/01/dry-lining-with-marmox-multiboard/

 

[One Day]

Ah, marmox is one manufacturer I've never used.
I know their coating is a little tougher than others, maybe it helps?

 

[Flintstone]

Maybe it does help, maybe there more confident to say 12mm is fine. 12mm is pretty rigid, I can’t imagine it causing any issues. I find the coatings can be quite inconsistent on various board manufacturers boards.

 

[Dan Fitchie]

I'm going to try and get hold of some Marmox but I've not found a local stockist so far. Short of that will there be a massive difference to using a tanked moisture resistant plasterboard?

 

[Bond]

No problem using plasterboard. (Cheep as chips.)

 

[Perry]

Just normal plasterboard will do.

 

[Dumbo]

What tiles are you using