Overboard T&G floorboards with Hardi Backer Board or 12mm Ply?

[JaonsS]

hello

ive overboarded t&g floorboards with 12m wbp ply before, however ive never used hardie backer board.

I was going to use hardie backer board this time.
18mm T&G existing floorboards.
glue the HB down with rapid set flexi powdered adhesive and screw down with 25mm stainless steel screws every 150mm.

is this just as good as using ply?
is this better than using ply?

is there any reason that either ply is better to use than hardie, or hardie is better to use than ply?

Cost wise, if i just use the Trade Point B&Q price for the ply, and tile supplier for the Hardi this is how much its going to cost.

Bathroom 2300 x 2050

Ply:
12mm External Ply: 2x £21 = £42
Screws £2.50
Total = £44.50

Hardie: 6 x £9.6 = £57.60
Flexi rapid set tile adhesive 1x £12.50
Stainless steel screws £8.50
Fibre tape £5
Total = £83.60

Labour is more for the Hardie too.


Not a huge difference in price really, so is there a difference?

Thanks for any help.

 

[White Room]

Hardie is more stable than ply.....

 

[JaonsS]

I forgot to say, its 6mm Hardie Board

 

[JaonsS]

so best to use hardie then i take it.

 

[White Room]

Glue and screw the Hardie, just make sure the floorboards aren't loose, if they are just secure.

 

[JaonsS]

great thanks for the quick reply.
i assume you screw it straight away as soon as you have stuck it down?

apply the adhesive to the floorboards, put the hardie down, stand on it and screw it in place?

will standard stainless steel 25mm screws be okay to use rather than the official hardie screws? the supplier said to just get stainless screws because its cheaper.

thanks

 

[White Room]

I fix all the boards then screw, get the spax 25mm screws from screwfix/toolstation.
Use a cement based adhesive s1 preferred with a 6mm trowel, drop 6mm hardie down and walk on them just to bed them in.

 

[JaonsS]

I was going to use the Tops Tiles Toppfix rapid set flexible powdered. I assume this is okay to use.

 

[White Room]

I'd do a standard set personally, after screwing the floor will get quite solid.

 

[JaonsS]

ok great thanks for info

 

[Kyle Knowles]

I was going to use the Tops Tiles Toppfix rapid set flexible powdered. I assume this is okay to use.

I usually use tile master adhesives or weber when I can't get it but the last few days I be bin using the top fix as there's a store half mile from the job I'm at and I've bin pleasantly suprised it's really nice to work with

 

[Kyle Knowles]

I usually use tile master adhesives or weber when I can't get it but the last few days I be bin using the top fix as there's a store half mile from the job I'm at and I've bin pleasantly suprised it's really nice to work with

top fix flexy white forgot to say

 

[flynny]

great thanks for the quick reply.
i assume you screw it straight away as soon as you have stuck it down?

apply the adhesive to the floorboards, put the hardie down, stand on it and screw it in place?

will standard stainless steel 25mm screws be okay to use rather than the official hardie screws? the supplier said to just get stainless screws because its cheaper.

thanks

Stainless steel screws would cost a fortune definitely cheaper I think your supplier may have his wires crossed

great thanks for the quick reply.
i assume you screw it straight away as soon as you have stuck it down?

apply the adhesive to the floorboards, put the hardie down, stand on it and screw it in place?

will standard stainless steel 25mm screws be okay to use rather than the official hardie screws? the supplier said to just get stainless screws because its cheaper.

thanks

 

[flynny]

Not cheaper

 

[Flintstone]

A lot better than ply.
Ply can rot or warp when wet, expand and contract with temp changes, the adhesive bonds a lot better to hardie. The height build up is less with hardie, no brainer!

 

[JaonsS]

ok thanks
150mm or 200mm centres for screws?
thanks

 

[JaonsS]

also,
3.5 x 25mm (6 x 1") or 4.0 x 25mm (8 x 1") screws

thanks

 

[Paul Smith]

4 x 25mm 😉

 

[emmettcraik]

Remember to leave a 1-2mm gap between sheet junctions for expansion. If it is going to be a wet room, seal the gaps with Silicon compatible with the waterproofing membrane you are going to be using over the top.