cutting cementboard with 4.5" grinder diamond blade
 

i have discovered that by far the most efficient way of cutting cementboard is with a grinder and a diamond blade. this is far better than d...ing around with scoring it with a utility knife and having to do it until the cows come home and then trying to break along the score. sorry, i just don't have the patience for that. i want it cut and that's that...

however, the question is that of safety and dust inhalation. when doing that, i do wear a gas mask type respirator. there still is dust EVERYWHERE so i do it outside. how protective is the respirator in this case? and how harmful is the dust that sets on the ground if it doesn't get vacuumed right away?

thanks

That's a messy job----but done frequently by pros for the goofy cuts--One good score with a knife works for me--

I have a 4" diamond bladed circular saw---with that ,you slap a sponge full of water against the blade and the dust is not a problem---

Rock dust isn't good for the lungs or your hair--the grass won't mind---If you are doing a lot of this type of work---buy a wet cutting circular saw---Harbor Freight has a nice one for cheap--Mike---

I found a ciruler saw with a 5" blade on it with a water line built right in that blows on the blade.
I got it at Lowes in the tile area.

sure but do you need water just to alleviate the harmfulness or does it make difference in cut quality? because my cut with a $10 Huskey diamond blade was no short of spectacular.

Doesn't make the cut better---but the dust will really irritate a customer--so most of us use water

The circular saws spin slower than a grinder so using a soaking wet sponge works just fine--

For one job? Make dust--cough twice and sweep up!