I bought some of James Hardie Trim made of fiber cement and I'm wondering what the best option is for cutting it is. Home Depot refuses to cut it because it ruins their saw blades.

Scoring this stuff on the back like you do the thin cement board isn't going to give me a clean cut. I saw they make 8 tooth carbide saw blades but don't want to fork over the cash if they don't last more than a few cuts. Was also thinking of trying the disposable fiber-reinforced abrasive wheels but this cement might chew that up pretty fast.

Any real comparative experience between these methods?

  • 3
    They make blades for fiber cement: google.com/search?q=hardiblade
    – DA01
    Jun 20, 2013 at 0:03
  • The best way to cut it is with a set of siding shears. I would look to rent them if you only need them for a while. Jun 20, 2013 at 3:24
  • Score and snap. Doesn't take that long and any power tools are bound to screw it up. Jun 24, 2013 at 20:01

1 Answer 1


There is a link to a complete installation guide for this type of fiber cement board at the supplier link in your posting.

From that guide it says:

Always cut the material outdoors.

Never cut the material indoors.

Never dry sweep accumulated dust - Use wet suppression or HEPA Vacuum.

For the outdoor application:

  1. Position the cutting station so that the wind will blow dust away from user and others in the working area.

  2. Cut with one of the following methods:

    a. Best:

    1. Score and snap
    2. Shears (Pneumatic or Handheld)

    b. Better: Dust reducing circular saw equipped with a HardiBlade saw blade and HEPA vacuum extraction.

    c. Good: Dust reducing circular saw with a HardiBlade saw blade (only use for low to moderate cutting).

NIOSH-approved respirators are recommended for workers when using the above recommended cutting practices to further reduce dust exposures.

This is what a cement board cutting shear looks like (click through for amazon link):

enter image description here

This is what a HardiBlade looks like:

enter image description here

  • Curiously the guide doesn't have the best method listed, but then "James Hardie recommends always using “Best”-level cutting methods where feasible."
    – BMitch
    Jun 20, 2013 at 12:46
  • Found the "best" method here
    – BMitch
    Jun 20, 2013 at 12:49
  • Hope you don't mind my answer-jacking. Didn't want to post a second answer when you had all the other details from the guide already.
    – BMitch
    Jun 20, 2013 at 12:54
  • I highly recommend the shears. I have used the hardiblade. The whole process of cutting HB with a blade sucks. Dust is everywhere - the silica is about as bad for you as it gets. Do it outside for sure. The blades last about 20 boards.
    – DMoore
    Jun 20, 2013 at 15:18
  • Be sure you're comparing the diamond Hardi blade and not a carbide. The Diablo (by Freud) or the Hitachi are currently the only diamond options
    – HerrBag
    Jun 20, 2013 at 17:40

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