[AndyL]

We recently put tile down in a bathrom and had a sheet of Cement Hardie Board left over by the installer. I was thinking of cutting it and using it for workboards. I''ve only got a jig saw. Can it be cut with that and is there a special blade I need?

[Bruzbt]

I have used Hardiboard extensively around my studio, table tops, gas burner enclosure, etc. This stuff eats saw blades and drill bits for lunch. The best way I have found to cut it is to use a box cutter knife to score the surface and snap it over an edge of a table or similar. The is the same as with sheet rock. The blade will dull after a few cuts but they are relatively inexpensive. Hardiboard absorbs water quickly so make sure you can keep an eye on it so to keep the piece from extreme localized drying.

Bruzbt

[D-Walk]

AndyL, on 09 August 2012 - 11:35 AM, said:

We recently put tile down in a bathrom and had a sheet of Cement Hardie Board left over by the installer. I was thinking of cutting it and using it for workboards. I''ve only got a jig saw. Can it be cut with that and is there a special blade I need?

[D-Walk]

You've got two main options. One, is to get a cement board scoring tool from a home improvement store like Lowes. It's got carbide tips on it, and you simply score then line you want on the board several times, and then snap it. They'll probably never go dull like a knife or something. If you're cutting a lot of cement board, you may think about switching out the blade on your circular saw (if you have one) for a cement cutting blade. It's a blade designed specifically for this...it will create a LOT of dust though, so do it outside or something. I use Hardiebacker board in my classroom for wedging surfaces, working bats for projects, and in my home studio. It's a great option because you can get a good number of boards out of each 3'x5' piece. Just make sure to get the 1/2" thickness.

[ayjay]

I have to use this stuff at work sometimes, it eats ordinary blades of any description, either use a throwaway handsaw if you don't have very much to cut (and then throw it away) or my preference is a tungsten blade in the jigsaw - these are not cheap, (probably about X 10 in cost compared to a normal jigsaw blade) but will last for a very long time even cutting Hardibacker or Aquapanel or whatever you call it over there.

[Marcia Selsor]

Unless you are doing facny shapes, straight cuts are was with a plain old utility knife. Score the board and have a 2x4 along the inner edge of the future cut.
Hold the inner board after scoring and whack it with a good one. It will snap. Then shave with a shur form to clean the edge.
Marcia

[JLowes]

Just snapping it along a straight edge of a table will make a reasonably straight line for ware boards. I did the score,score and snap, but I realized that I just didn't need that straight of a cut for that much work and blade wear, and sawing generated too much dust for me.

Like Bruzbt said, they absorb water quickly. I sometimes use that to my advantage to quickly dry overly wet clay to a wedgable consistency. I have also used the boards for a throwing bat, like you would use a plaster bat, and found that dipping them into water first helps with getting them to stay stuck down to clay on the wheelhead long enough to complete a piece; then they wick out water on the pot and the pot pops right off the "bat".

I found the 1/4-inch thickness fine for my uses, although I admit I have not used the 1/2-inch thickness.

John

[Denice]

Do you know which type and brand of cement board you have, regular Hardi Backer is not waterproof and may have not been used in the shower it just depends on the person who did the job. The cement board that is waterproof is harder to cut and a lot more dust. I recently finished a outdoor mosaic table and used a new product by Hardi Backer that is waterproof and bought a special circular saw blade but it was very had to cut and had a lot of dust still. You probably have regular Hardi Backer in your shower that it what most contractors use because it's easier to work with. If you have regular Hardi Backer in your shower just make sure you keep your grout lines repaired and sealed so no moisture can seep through to the Hardi Backer. With this type of maintenance you shower should last forever. Denice

[DavidD'Urso]

I experimented a lot with cement board and finally just started using my skill saw with one of the thin carbide tipped framing blades. They're inexpensive and just save that blade for use with your cement board projects. It cuts right through it like butter. Approach it and lay it out just like you would if you were cutting plywood. It's dusty so do it outside and wear safety glasses and a dust mask. You'll have to clean your saw a little when you're done too - of course.

[Mark C.]

DavidD, on 11 August 2012 - 11:51 AM, said:

I experimented a lot with cement board and finally just started using my skill saw with one of the thin carbide tipped framing blades. They're inexpensive and just save that blade for use with your cement board projects. It cuts right through it like butter. Approach it and lay it out just like you would if you were cutting plywood. It's dusty so do it outside and wear safety glasses and a dust mask. You'll have to clean your saw a little when you're done too - of course.

This above post is the best way to make a clean cut without buying a special hardie blade.
Mark