Cement Board

[CJ]

25mm Hardi. :yikes: Can imagine humping 25 sheets of that about.

 

[IHB]

Yes for the pep but no for circular saw mate, the blade will just burn. I'd check what hardie recommend for cutting. I do have concerns about the safety of this stuff tbh

I think they say low dust (diamond) blade in a circular saw with dust extraction or a strong wind.

Doesn't sound like it'll be fun and not a job for indoors.

 

[AliGage]

30Kg a board. Not that heavy. Similar to fermacell boards so cut with a circular saw

 

[Time's Ran Out]

so whats the answer? new products like cement boards or stick with ply which has stood the test of time and much cheaper?

But that's the issue - it hasn't stood the test of time!
Plywood moves, cracks and can debond. When you take into account the additives required when fixing to plywood it makes the preparation more expensive. How many fixed tiles to plywood using a bottle of Ardion 90 and a bag of X7 - not much short of £30! The tiles would stick but the hairline crack would always appear at 4' and 8' joins. And today's plywood is over £25 a sheet and that's only 12mm containing too much moisture.
A mask, dust extractor and outside is the simple solution to cement boards.

 

[IHB]

No guarantee it won't crack along joint lines the same as ply. The joist will still move & the joint is the weak link.

 

[John Benton]

I have just had to replace 3 tiles in an en-suite that I tiled about 7 months ago in a new extension. The floor had dropped 4mm, and when I removed the tiles the cement board was literally torn apart along the crack of the tiles. It was not on a joint in the cement boards either but it appears it was a joist that had either dropped/shrunk causing the problem.

 

[johnplum]

Interesting discussion. The problem of a new suspended floor for bathrooms maybe cannot be solved completely.
Anyway, it has to be 25mm ply for good reason, then