cutting Hardy Backer 1/2 " boards

I am rebuilding an old bathroom and have purchased Hardy Backer Board 1/2"x36"x60" sheets to use around the bathtub/shower area. I am working with this type of product for the first time. I have a tungsten carbide blade hand cutter to score the sheets and a similar blade for the jig saw as well as the appropriate screws as per instrucions. My first attempt to cut a sheet hasnt gone well yet. While the sheet scores well it doesnt want to separate. I dont want to ruin the cut.
Question is can anyone tell me the proper way to cut them?

Join the club!

Hardie says all you have to do is score the board and break it just like drywall. They are full of crap.

It is easier using the special scoring tool and even then it takes many passes with the tool before the board will break cleanly, otherwise the edges are jagged.

The dust created when sawing is very dangerous stuff and should be avoided at all times.

All you can do is what you are doing unless you own a pair of the (also special) shears made to cut the stuff.

The truth is the edges don't have to be perfect because they will be taped and covered with thinset at some point. Just try to avoid a seam on a stud, that's an even bigger kick in the butt.

I think one thing is that you should bend the board exactly opposite from the way you bend drywall after scoring,.I. E bend toward the scored side. It worked OK for me with the 1/4" hardi if I scored deeply - I don't know about the 1/2".

You do bend it back wards, toward the score line. But on 1/2" it is best to score both sides several times for a clean cut. I use the RazorBacker shears.

Buy a masonary blade for your skill ($8) saw for just a few cuts, get a dust mask.

Home do-it-yourselfer.
Thanks to all for the help.
Using the scoring tool would have taken forever on half inch hardy backer. In the end I used the tungsten carbide blade on the jig saw. It performed great. I made all the cuts out doors and wore a mask but your right Im still worried about breathing any of that dust. After reading their warning I actually find it scary seeing as you are absolutely going to have to cut and work with this stuff.

I made all the cuts out doors and wore a mask but your right Im still worried about breathing any of that dust. After reading their warning I actually find it scary seeing as you are absolutely going to have to cut and work with this stuff.

That's why some of us use the shears. A good investment if you intend to do a lot of Hardie.

That Hardi is already real dusty, even before you did that dry cutting. Be sure to wash it all down good and then re-wet it again before you thinset over an area.

Makita Grinder with the mason wheel
Quicker and easier than scoring
Mark your measurements and snap a chalk line
Cut outside, Dust will carry away