Now I’ve done 6mm and just scored and snapped. Simple.

Hardiebacker site suggests it’s just as simple for the 12mm…

.. however the Internet suggests super sharp angle grinders, blunting Stanley blades at the sight of 12mm, jigsaw death, impenetrable to lasers etc.

Anyhow cut this thickness by score and snap?

Edit: It’s a bit spendy, just spent £50 on 5 sheets, hence not wanting to just experiment!

Ta.

I had limited success in snapping it to be fair. It’s horrible stuff to cut.
But if they say you can snap it, I’m sure you can. Just reckon on trashing a few blades.

I ended up buying some cheap jigsaw blades and changing them very often after struggling with the snap.

I scored mine well and tried to snap it with my foot increasing the pressure over a length of wood. It snapped, but not entirely down my score line and I had a very ragged edge after.

Can’t really say anything to encourage you sorry 😐

I just used an old wood saw then removed the rough edges with a sanding block.

Just score it a couple of times with a sharp blade and it snaps perfectly well.

One blade will easily last enough cuts for 5 boards.

I use the stuff regularly.

Robz, do you ‘kick’ back from behind the score, as you would plasterboard, or kick down onto the disposable piece? (The latter of which the official hardiebacker video shows, which seems odd!)

Thanks

Another vote for using an old wood saw.

Sorry just saw you question. I treat it exactly like plasterboard and kick from the back.

Only difference is I score it two or three times

Thanks Robz, I’m putting my complete faith in your advice and will be boarding tomorrow – I’ll let you (and the googling world that lands here!) know how it turns out 🙂

Just done some today. If you score and kick back, you get alot of material left on which then requires shaving down. We use hardie floor and hardie board and have one of the 4 tooth circular saw blades which helps keep dust down.

I had the proper hardie scorer knife thing, but still couldn’t get a good cut.

I used an angle grinder in the end – Dusty but much neater cut..

DrP

I can confirm (for anyone random googling) that scoring it with a normal (not carbide) Stanley blade a few times (about half a dozen) so the cut is a few mm deep, then just laying the scored area over the other boards and standing on it…

..works perfectly. Really clean snap. Make sure the cut goes in a few mm though.

I use a saw…. doesn’t take too much longer

I use an angle grinder with a Porcelain tile blade. V. Dusty but hot knife through butter.