Should Hardiebacker boards be used or not?

[Ian]

Thanks gentlemen for you advice.

Sounds like the Hardibacker boards should be used.

One thing I’m a little confused by; The Hardibacker instructions state “Apply a gap filling bed of non-flexible tile adhesive to the subfloor using a 6mm notched trowel.” Does this mean, in my case, that the non-flexible tile adhesive should be applied direct to the P5 chipboard flooring?

If it does, then I don’t understand why you can’t apply flexible adhesive directly to the P5 chipboard flooring and fix the tiles directly to the P5 chipboard flooring?

The hardie boards are screwed down, the tiles won't be. A cement board is a far more stable substrate to tile to, it does not swell or warp if it comes into contact with moisture, chipboard will.

 

[Rookery]

I always use RSF + screws to overboard a timber floor. I cant see why a non-flexy is recommended over a flexy adhesive.
However, taking the instruction that the adhesive is a 'gap filler' i.e. for cupped t & g floorboards, would it not then be ok to merely screw the Hardie down onto a perfectly flat chipboard floor with no addy at all? Come Mr Hardie we want to know.

 

[Rookery]

HardieBacker is a Cement based board that provides a suitable surface to tile on to. Unlike wood, it does not expand and contract with exposure to water. Attached is a copy of the HardieBacker installation instructions.

If you are looking for an additional document to source take a look at this NHBC Standards – Section 8, Part 3, Para D4

TILES ON WOOD-BASED SUBSTRATE
The floor should be designed to take the additional loads of tiles and any other materials (e.g. overlays). Tiles should be suitable for laying over a timber base.
The floor decking should be: chipboard floor decking overlaid with minimum 10mm plywood suitable for exterior conditions and fixed as above, or proprietary separating/de-coupling layers, tile backer boards or tile bedding reinforcement sheets used in accordance with the manufacturer's recommendations.

I hope this helps

So NHBC standards are lower than BS5385. No wonder todays houses are such crap.

 

[kilty55]

still plenty people who tile to chipboard , after seeing so many failed jobs on chipboard some of which will take time to fail i wouldnt advise tiling onto it definately go the cement sheet route aquapanel for me

 

[widler]

i agree use hardi,its great stuff .

 

[charlie1]

HardieBacker is fastened to the subfloor with nails or screws, not exactly with the adhesive. The intent of the cement based adhesive is not to make the board stick to the subfloor, but rather to be used as merely a gap filler to minimize the imperfections of the floor. The installation system has been rigously tested and HardieBacker performs best when all of the steps in the installation guide are followed.

i can see why it would perform better using non flexible adhesive, the combination of the hardie and the adhesive becomes one solid slab rather than hardie with a flexible bed which could theoretically have slight movement.

 

[jason67]

I will definitely be using Hardibacker boards

Picking up on what Rookery said; as Hardibacker recommend laying the boards on non flexible adhesive for GAP FILLING purposes only, and seeing as my chipboard flooring is dead flat, then should my boards just be screwed down without using adhesive?

 

[Gazzer]

You can only go with what the manufacturer states, if you dont then you are on your own should anything happen.

 

[Ian]

Should Hardibacker boards be used or not?

I will definitely be using Hardibacker boards

Picking up on what Rookery said; as Hardibacker recommend laying the boards on non flexible adhesive for GAP FILLING purposes only, and seeing as my chipboard flooring is dead flat, then should my boards just be screwed down without using adhesive?

I'd still stick them, it's good practice IMO

 

[Ceramico tiling]

I don't believe the guy has been tiling long if he says he can tile onto chipboard.