Uneven hardiebacker on victorian terrace bathroom floor

[Ross tile]

Hi there - so i have ripped up the old tiles and old layer of ply and cork. Replaced with 12mm hardiebacker screwed in along with a layer of adhesive between the backer and the floor. There is some discrepancy of maybe 5mm between aome of the boards. Do i need to start again? Im using flexible adhesive and the room is around 1-2m2.

Current plan has been to rip up the problem boards and reapply

Any advice would be great!

 

[Ross tile]

I.e. What sort of tolerance is okay and can be dealt with by using more adhesive on the tiles

 

[J Sid]

if the floor is solid, put a bag of SLC over the whole floor

 

[Ross tile]

Its old wooden floorboards with a number of small gaps unfortunatrly.

 

[Spare Tool]

Its old wooden floorboards with a number of small gaps unfortunatrly.

Prime and level after you've fitted the hardi and taped the joints

 

[Ross tile]

What would be an example product / primer?

Is it normal for the hardi not to be exact and to use a primer?

Thanks

 

[Spare Tool]

Personally I prefer Tilemaster levelflex and would use there primer, but most reputable manufacturers make a leveler suitable. Your boards will only be as flat as the floor your screwing them to..

 

[Time's Ran Out]

I’ve found that the 12mm Hardi can be of varying thickness.

 

[J Sid]

if you have any gaps round the edge fill with expanding foam, also use to create a dam across the door.

 

[Waluigi]

Be careful with HB. Often it can be poorly stored and as it’s such a rigid material, if the base of the storage pallet (or whatever) isn’t flat then every last board will be on the wobble. I hate the stuff, especially the 12mm