Hardibacker laid with no adhesive.

[Sean Kelly]

You can if it just to fill the voids! You can then use the fastflex (oh the joys!) to stick the tiles to the Hardie. If ti was me, and they were spec-ing dry lay Hardie I wouldn't do the job. I haven't yet seen a sheet of 6mm hardie that is "flat"!

Funny you say that Grumpy about the flatness of Hardi. I saw 3 sheets of 9mm Hardi 2 weeks ago. They were in with the sheets of 6mm. I know what you are going to say.....Hardi don't make 9mm sheets!
Also, Sorry, I thought because of the water content in SPF and the unstableness of chipboard that it was a no no to use it. Cheers Sean

 

[Rob Z]

....... plus 13 boards of Hardibacker @ £12.49 a board.

Sean, off topic here....it sounds like Hardi is quite expensive there. Hardi here is less than $10 a sheet , either 1/4" or 1/2" (6mm or 12mm?), for 3' X 5' sheets. I think $10 is equal to ~6 GBP.

And then I have seen on this site pricing that you guys have for some materials that is a lot less than we have here.

But most importantly, I think your beer prices are a lot lower.

 

[Thespanishtiler]

you can get hardie board for less than 10 quid for the 900mm x 1500mm - 6mm thick

I use mapei or benfer spf with a trowel notch selected acording to the likely deapth of any void, use good quality screws (turbo gold) and grid these out at 200 mm ctrs.

this is how i do it and it works, i have never had a failure.

probably laid over 200m of board since i dropped ply 18 months ago.

personally, the opinion of a rep or tile shop staff is of no relevance to me when i spec a job and if some one trys to dictate to me how to do some thing i will decline the work, so I am with you on this one Grumpy.

the choice is yours Sean

 

[Alberta Stone]

If they are spec-ing to dry lay a cementitious underlay....they are nuts.
Those boards, in particular the 1/4 inch offer zero structural support, just a smooth surface.

I do know how stubborn the chain of command gets at times, so if they insist on their orders just make sure that it is "specified" in writing as you could put the tiles in upside down and not be liable if such was specified by those who hold the warranty.

BTW, how thick is the actual deck under the lino and how is the subfloor constructed?

 

[Sean Kelly]

Took the lino up and found 18mm T&G chipboard nailed onto joists. I banged in the nails and screwed screws into the joists. I then layed the Hardiebacker 6mm onto fastflex (used 6mm square notched trowel). The thing I find with the Hardibacker and the Hardie screws is that some screws drive in nice and flush to the Hardie. Some screws go straight through the Hardie. About 6 screws per pack of 100 were defect and could not be used at all. Will find out the name of the chipboard for tomorrow. Cheers Sean