Blades for cutting Hardie (fiber cement)

[Steve Keathley]

I've been looking online, and the only thing really advertised for this are the Diablo blades (I know to get the diamond tipped version). Are there any other blades that will work as well or better than the Diablos?

[Rich Engelhardt]

I use the regular ~ $20.00 Freud Diablo from Home Depot - the 7.25" 40T ones for long straight cuts.
For shorter cuts, I use carbide grit jig saw blades.

I've probably gone through two dozen sheets of cement and Hardi board with the same Diablo blade and it still cuts through 2x4's like butter.
Just slow down the feed rate, cut the stuff outside and wear a good respirator.

[Gus Dundon]

How about hitachi blades? I just saw it in amazon.

[Steve Rozmiarek]

Freud Diablo hardie blades are good. I bought a couple for the tablesaw, and have yet to kill one. Also have a couple Irwins, the Diablo is better. Like Rich said, regular blades work, but the hardie approved blades last much longer.

[Sean Kinn]

How much do you need to cut? I've done several tile jobs with just the hand-held scoring tool and a long straightedge. Score the board about 4 times, and snap.

[Kevin Bourque]

I've used Hardi-backer hundreds of times. Never once needed any power tools other that a sabre saw for circles or other irregular shapes. It cuts just like drywall;just score it and snap it.

[Steve Keathley]

I've used Hardi-backer hundreds of times. Never once needed any power tools other that a sabre saw for circles or other irregular shapes. It cuts just like drywall;just score it and snap it.

I've done that on the backer as well, but I need to do some trim work and will be using my miter and table saws to get clean, tight joints. I'm going to be trimming out some pilings, replacing the facia and window trim, and adding about 350 battens to the exterior.

That's more cutting than I want to do with a utility knife and straight edge.

[Peter Kelly]

You might consider buying one of these: http://www.cpoindustrialpowertools.c...id=makita-saws

Hardieplank can be pretty nasty stuff to work with as it generates a ton of of fine silica dust when you cut it with power tools. That saw is expensive but silicosis is not something you want to get. Not great to get abrasive dust in your woodworking tools either.

[John C Bush]

I used a masonry "blade" and the dust was incredible. Just as I was finishing my project, a contractor friend stopped by and showed me how he uses a power shear for cutting the Hardy plank. No dust, clean cut,s and faster than my blade. I would definitely consider it even if your project is of modest size. Good luck, JCB

[Steve Keathley]

Power shears. That's an interesting idea.

[keith micinski]

I bought some cheap carbide blades and they were terrible. I used the Irwin blade specifically designed for fiber cement. It did a much better job but still didn't last very long. Also I had no luck finding a 10 inch blade to put on my sliding mitre saw. I think a quillotine cutter and a shear are the best way to go if you can do it.

[John Schweikert]

I just finished installing Hardie trim and Hardie plank siding to my 8'x14' garden shed (to match the style of our house). I bought a Hitachi 7-1/4" polycrystalline diamond blade specific for fiber cement to use in a worm drive saw. Purchased from Amazon (where more than half of all my woodworking and building tools come from). Blade worked great for the planks. For the trim I just used the 24 tooth framing blade I already had on the 12" miter saw. I knew from past experience cutting this stuff that the blade would be destroyed in short time but that blade was far cheaper than a $90 12" Hitachi PCD blade for Hardie cutting.

Hardie trim is brutal stuff. It can chip easily in just handling and installing. It has zero forgiveness in less than flat surfaces it goes on. It's a pain to nail by hand. I used my NT65MA4 nailer with 2-1/2" galvanized nails and that worked fine. Issue always arises when you happen to nail through the Hardie trim and the nail hits another nail head and bounces back completely and curlicues on the trim face.

The only two redeeming qualities of Hardie trim and planks are attractiveness and longevity. Install can be frustrating whereas wood trim and siding is far more pleasing to do.

Look at Amazon, they have a ton of blades of all sizes for fiber cement from many brands, Hitachi, Freud, Irwin and others. I would also take a look at Pactool shears which cut the planks but not for trim. Hitachi makes jigsaw blades specific to fiber cement too. I opted not to buy jigsaw blades and used normal wood blades, which I already had a bunch, knowing they would be destroyed in no time and they were. I ate up 4-5 jigsaw blades, each makes about 6-12 inches of cutting before the teeth are completely removed. I just use the jigsaw to finish out corner cuts to fit around windows and doors in the planking.

If you want tight jointed trim, then a miter saw saw blade is the best choice. But realize that Hardie trim does not have a perfectly squared profile, it can have slightly slanted sides in relation to the faces which makes joints a huge pain in the rear. Hardie trim either fits into the space you want or it doesn't, there is no wedging or tapping in like wood. Hardie trim will just fracture if forced. Have fun. It took me several days to trim and plank the shed. Wear a dust mask and eye protection!

[Jim O'Dell]

I ran through a couple carbide blades in my circular saw when I did the Hardi-Board on my shop. Carbide is gone very quickly! I was thinking the special blades had like 3 or 5 teeth? The also make shears that add to a drill. Not sure how good they are. And doing this with my circular saw killed the saw. Just like cutting Pavestone retaining wall blocks with my old RAS. And Peter is right about the dust. Make sure you have good dust mask for this. Read the Hardi web site on health risks. Jim.

[John Schweikert]

Yep, the Hitachi 7-1/4" PCD blade has 4 teeth. Other do 6, varies with manufacturer and blade size. The PCD blade cuts well and leaves what appears to be a little fuzz to the fiber cement edge, but wear gloves and just run your hand over cut edges and it cleans up instantly for crisp edges.

I have no idea how many cuts I made with the PCD blade or total length of cutting, but it cut just as well on the last cut as it did on the first. It was well worth the $40. In a few years when I build a two story garage, I'll buy the 12" miter blade version for certain, or better yet the shears which supposedly make just perfect cuts and zero dust.

[Rich Riddle]

I have been reworking a master bathroom and using a DeWalt DWC860W 4.5 Inch Wet/Dry Masonry Saw on the concrete board. It hooks up to a garden hose and works like a charm. I have snapped it many times but needed more precision work. This saw delivers.
http://www.amazon.com/DEWALT-DWC860W.../dp/B003BVW5NU

It's one of only two DeWalt tools I own. The other is being used in the same project, a 90 degree laser, DW060K.

http://www.toolup.com/dewalt_dw060k_...FQSg4Aode2gA0w