HardieBacker is the best-selling cement-based backerboard on the market. It is the best choice for home improvements and construction in wet areas like bathrooms and kitchens, thanks to its lifetime warranty and MoldBlockTM technology.
Its offered in either 3×5 or 4×20 cm sheets, in two different thicknesses – HardieBacker 500 (1 cm), and HardieBacker 1/10 cm. The 500 is used for underfloor and behind walls, while the 1/10 cm is used as countertop underlayment. Both are excellent underlayments for tile, and the 500 can be used to paint or wallpaper.
HardieBacker board is made of 90% Portland cement, ground sand and no paper facing. This is because mildew can feed off of paper. It is also free of asbestos, formaldehyde and gypsum, which is a major advantage over other backing boards.
This PDF specification chart compares HardieBacker to other backing board materials on the market.
HardieBacker board can be cut and worked with with ease using the right tools, even when it is necessary to make difficult circular or angled cuts around corners, pipes, pipes, or showerheads. In fact, the 1/10 cm board is manufactured with EZ Grid TM perforated grooves, which make smooth cuts and ultra-detailed work much more achievable for the amateur.
Cutting: Tools, Tips, And Techniques
For long, straight sections, the recommended method for cutting HardieBacker board (or any cement backing board for that matter) is the score and snap method. A special carbide-tipped scoring tool will make it easier, but a general utility knife can also be used.
Simply lay the board flat on the ground and mark your line using a straight edge. Then, use the scoring knife to apply firm pressure to the line. After you have scored the board, put your body weight on it to keep it down. Then, snap the score up to remove it.
The score and punch methods are effective for small angles, circles, and curves. Mark the circle and then score it. Next, score some cross-sections like you would slicing a pizza. Next, using a hammer, start in the center of the circle and simply punch out the scored section.
You can do the same thing for squares, angles, and corners; simply mark and score the desired area, score cross sections, and break away the area with a hammer.
Here is a good video example of how to properly execute this technique:
Drilling holes along your desired line with a masonry bit will also work, but this is a longer process and doesnt produce as clean a cut as scoring.
Cutting HardieBacker Board With Power Tools
The score and snap method is really the only option for cutting HardieBacker board if youre working indoors.
Power tools can certainly be used as well, as long as youre in a well-ventilated, outdoor area. The silica dust that cement board gives off when cut with a saw is not something you want floating around the inside of your home.
Wear goggles and respirator protection if you use any of the following power tools.
A circular or jigsaw is best for long straight cuts. For the easiest, cleanest cut possible, youll want a carbide-tipped blade with as few teeth as possible. The more teeth you have on your saw blade, the more dust it will produce and the more rough the cut. This 4-tooth HardieBlade from Diablo is actually specifically designed for cutting cement board. This less expensive, 6-tooth blade will also work well.
The same applies for jigsaws; use a coarse, carbide or diamond-grit blade and move slowly for the cleanest cut. You’ll use a lot of blades so be prepared to change them often. A jigsaw might be a good option if you have a large hole or square to cut out.
You can also use an angle grinder with a diamond-impregnated cutting wheel, but this will produce lots of dust. It would be a nightmare to keep a straight line.
If money is not an issue or you plan to cut lots cement board, then a pair electric cement shears such as these Makita are another option. The cut produced is excellent, but with a price tag north of practicality is more or less thrown out the window.
There are many options for HardieBacker cement boards to be cut. Take your time and select the right tool for you.
Last but not least, when using power tools, be sure to wear safety gear and work outdoors.
