Hardboard siding provides an alternative to wood or vinyl for covering the exterior of a home. Hardboard, also known as cement fibre siding, is a relatively low-maintenance product that is easy to paint and seal, making it an easy choice for homeowners looking to install and forget. When installing, you will probably have to cut some of the siding pieces to fit properly on the wall. However, using basic woodcutting blades will serve only to waste your time, since those blades will quickly become dull against the hardboard. Instead, use special blades to carefully and accurately cut the boards.
Wear a dust mask and protective goggles when cutting hardboard siding. Fibre cement produces more dust than regular wood siding, so you must protect yourself.
Set up your work station outdoors to avoid making a mess with the dust. Cover any nearby bushes, cars or other objects with tarps to protect them from the dust.
Attach a tungsten carbide blade to a circular power saw. These blades are specially designed to withstand the hardboard.
Lay your piece of hardboard face down on your workstation. Score your cutting line with a utility knife to give you a guideline to saw.
Cut through the board with the circular saw, starting at one end and working your way through the board. If necessary due to thickness, make multiple shallow passes with the saw instead of a single deep pass, to ensure that you cut directly into the scored line. Continue until your cut is complete.
Many professional installers use siding shears to cut hardboard. These shears are extremely effective and can limit dust, but are also extremely expensive and not worth the price for a single installation. If you want to try these shears, check with local hardware or rental stores to see if you can lease shears for a single project. Some professional saws include a dust collecting mechanism. These types of saws can help you cut down on the mess from cutting hardboard.