Hardboard siding is a cement and fiber product that is used on the exterior of many homes today. It has the same look at vinyl siding, but is much harder and provides better insulative protection for the home. This hardboard siding is coated with a primer in order to reduce the amount of water saturation that can happen when it rains. The ends must also be primed before they are installed to continue blocking any water from soaking into the hardboard. Due to improper installation, or through years of use, this hardboard siding is prone to fail or sustain damage. When you notice any damage to the hardboard siding it must be replaced immediately.
Step 1: Pry Damaged Area
Slide in a small pry bar under the damaged piece of hardboard siding. Take care not to pry it completely off, you only want to loosen it up so that you can manually remove it. You may need to pry off some of the surrounding pieces if they are also involved with the damage, or if there has been damage to the sheathing underneath.
Step 2: Remove Damaged Hardboard Siding
Manually loosen the hardboard siding with your hands instead of continued prying after they are loosen. This will minimize any other damage to the area. Try to remove the entire piece of hardboard siding for better integrity of the exterior.
Step 3: Inspect for Other Damage
With the damaged hardboard siding removed you can now inspect the sheathing underneath for any other repair that is needed.
Step 4: Measure Hardboard Siding to Fit
Measure the section of siding that is missing. Do this with the section of wall where the new siding will be installed, not with the old piece of hardboard siding. Transfer that measurement to the new piece and begin to make the cut with a skill saw and fine tooth blade.
Step 5: Cut Hardboard Siding
Lay the hardboard siding on a flat surface supported by sawhorses. Set the depth of the skill saw to just go through the hardboard siding. Make sure that the top surface of the siding is facing down away from the blade. Set the saw on the mark and slowly cut through the siding.
Step 6: Prime Ends
Once the cuts are made, prime the ends of the siding. This will protect it from any water damage. Let it dry before installing.
Step 7: Install New Hardboard Siding
Hold the siding up into position and slide it underneath the top section. Make sure that it overlaps the bottom by 1/2 inch. Secure it to the exterior of your home with masonry nails as close to the top as you can.
Step 8: Caulk Joints of Siding
Once the new piece of siding in secure to the exterior of the home you must continue with the weatherproofing. Use a new tube of caulking and cut the end so that a small bead will be released. Apply this thin bead of caulking around the entire area of the new piece of siding. Make sure it is continual and without any gaps between the siding and caulking.