Projects that involve Hardie Boards often require different cuts; it is almost like a prerequisite. Such a board, however, is not easy to cut and requires strength as well as precision. And because of its cement-like rigidity, completing this task is no easy feat—especially for inexperienced folks.
But the good news is that learning how to cut a Hardie Board is quite easy; you just need to have the right tools and basic techniques.
What Is Hardie Board for?
For a long-lasting and sturdy house exterior, construction workers highly recommend using Hardie Board. It is a cement board tile underlayment that is often paired with walls, sidings, countertops, and floors. It was created and works specifically for moisture-prone areas such as bathrooms and kitchens.
Made with 90% Portland cement, sand, and cellulose fibers, the Hardie Board also provides excellent adhesion for sidings and tiles. It is also known by its other names like HardiePlank Lap Siding, HardieShingle Siding, and HardieBacker.
Does Hardie Board Need Special Tools to Be Cut?
There are two types of cement board available today: a hard-like board and a lightweight one. Because each cement board varies in rigidity, if you ask whether cutting a cement board with precision requires a power tool or not, the answer will mostly depend on the material.
Is the board soft enough for a score-and-snap method? Or is it stone-hard and requires a specialized tool?
The rigidity of the board is not the only element to take into account, the person’s skill and experience must also be considered as well.
If you are an amateur, professionals recommend a specialized tool for easier and much more precise cutting. However, if you have some experience and knowledge of how to do it, then standard cutting tools such as a saw would work.
Having said that, here are a few tools you can use to cut a cement board:
- Cement siding blades
- Siding saws
- Score and snap
- Stationary shears
- Handheld shears
- Angle grinder
- Circular saw
How to Cut Hardie Board
There are plenty of ways to cut Hardie Board efficiently. You can use a regular cutting tool or a specialized one and get the same result – a cut board. There are, however, distinct benefits and drawbacks to each piece of equipment. And, depending on your knowledge, skill, and experience, the outcome may differ.
But before we proceed, make sure to gather the following safety gears first:
- Dust mask respirator
- Eye protection gear
- Hearing protection (optional)
Two Different Ways to Cut Cement Board
Ready and prepared, yet confused about what type of tool to use? Below are two methods (highly recommended for beginners) that you can try.
The easiest way to cut cement boards—especially for non-professionals—is to use regular cutting equipment. And for Hardie Boards, the most recommended method is the score and snap. This is particularly true for straight and long cuts or where you are working indoors.
Score-and-snap is a method usually used for cutting drywall. You will score the cement board (a Hardie board, in this case) and then cut it along the scoreline. For this technique, a carbide-tipped scoring knife is the best option possible because of its sturdy scoring tip.
But if you do not have one, a general utility knife will do the job as well.
Here is a step-by-step guide on how to execute the cutting technique:
- Start by laying the Hardie Board on a table or any flat surface, then mark the part where you want to score the board.
- Next place a straightedge across the board and kneel on it to ensure that it will not move. If you do not have the tool, you can also use a ruler or a piece of lumber.
- Once everything is in place, simply follow and draw the line along the straightedge. Make sure to apply enough pressure to ensure that the line is deep and visible enough to be snapped. Repeat two to four times as needed.
- Lastly, pick up the board and snap it along the score line using a utility knife, a carbide-tipped scoring knife, or your knee.
Using Power Tools
While the snap-and-score method is typically sufficient for experienced DIY enthusiasts as well as construction workers, power tools are great cutting options too. These tools can produce long, clean, straight cuts and are ideal for fast cutting.
Here are two of the most common tools used to cut Hardie Boards:
Angle grinder. An angle grinder is the preferred tool for fast cuts. Make sure to use a diamond cutting wheel too.
But do take note that running the blade of an angle grinder through a cement board produces clouds of dust that may be harmful to your eyes and lungs. So, make sure you are wearing all necessary safety gear detailed above.
While fast and accurate, this tool is much harder to use and control than a circular saw.
If you are looking to buy an angle grinder we recommend the Angle Grinder 7.5-Amp 4-1/2 inch with 2 Grinding Wheels.
Circular saw or jigsaw. Power tools like the jigsaw and circular saw are ideal if you are aiming for long and straight cuts. It is best to use a carbide-tipped blade too for circular saws, especially if you want clean cuts.
For jigsaws, you can use a diamond grit blade that is coarse.
A great choice you can go with is the SKIL 15 Amp 7-1/4 Inch Circular Saw with Single Beam Laser Guide it has a powerful 15-amp motor that helps cut accurately and fast.
But do keep in mind that these tools are only recommended to use while working outdoors or in a well-ventilated area. Hardie Boards, when cut, produce silica dusts, especially if you are using a blade with more teeth.
Should You Hire a Professional?
Learning how to cut Hardie board is essential if you want to learn how to install vinyl sidings. Anyone can learn how to do it, whether you are an amateur construction worker, a DIY enthusiast, or a homeowner.
But this job requires precision. And for unskilled, inexperienced individuals, there is a chance that you will make more mistakes than successful cuts. As such, it is strongly recommended to hire a professional—especially if your project is not merely a DIY project, but a vinyl siding installation.