How to Repair Hardie Plank Siding? DIY Ways to Deal with Siding Damage

Hardie plank siding is a traditional style of exterior wall cladding that has been around for decades. This type of siding offers great durability and weather resistance, but it can be damaged by the elements over time.

If you have hardie plank siding on your home or business and need to repair it, this blog post will provide information on how to fix common damages like peeling paint and broken boards in order to extend its life span.

Measure the Damage

The first step to repairing hardie plank siding is measuring the damage. In order to repair your hardie planks properly, you will need a good idea of how much material needs replacement in each area and approximately where on the paneling it should be added in relation to existing boards.

Plus, whether you actually need a replacement board or you can use putty to repair the existing ones is to be understood clearly before jumping into the work.


As a rule of thumb, you’ll need replacements if the boards go out of shape or they are broken so badly that there is no way of repairing them and having the same neat look.

Repairing Severely Damaged Hardie Planks

There are several steps for you to follow in order to repair a damaged siding-

Remove Damaged Boards

If one or more of the Hardie planks is severely damaged, the first step is to remove it completely. Pry off the plank using a pry bar or hammer and chisel until it comes loose.

If you are having trouble removing the board, use a saw to cut it along the seam where it meets the adjacent boards. This will allow you to remove it without damaging the surrounding boards.

Replace Damaged Boards

Once you have removed the damaged board, replace it with a new one by sliding it into place and tapping it gently into position using a hammer. Make sure that the replacement board is of the same thickness as the other boards and fits snugly against them.

You’ll need to use a hardie specific nail gun to install the new boards perfectly. If you don’t have one, hiring a professional is a better idea for occasional repair works like this. However, for people fascinated by DIY works, buying a tool is a better investment for the long run.

Caulk and Paint it

Once the new board is in place, caulk the seams between it and the adjacent boards using a tube of caulk. This will help to keep out moisture and prevent further damage.

Finally, paint over the newly installed area with a coat of paint that matches the existing color of your hardie plank siding.

Repairing Minor Cracks or Peel offs

In case the damage is not so severe and it is restricted to a few cracks or peeling paint, you can follow the steps below-

Use Putty and Paint

If your hardie plank siding has minor cracks in it, these may be filled using putty. You’ll need to remove loose pieces of cement from inside the crack with tweezers followed by filling it completely with a quality putty.

Once the putty has dried, sand it down until it is level with the surface of the plank and then paint over it using a brush or roller.

Caulk Seams

If your hardie plank siding has started to peel off in some areas, you can use caulk to stop the peeling and ensure that moisture does not get in.

Using a tube of caulk, fill the gaps between adjacent planks using a putty knife or caulking gun. Smooth out your repairs by running your hand over it to make sure there are no ridges left behind from tooling it with the blade.

Paint Over It

Before painting over the surface, make sure the putty has been dried out completely and has cured for at least 24 hours.

Once it is completely dry, mild sanding should make things smooth. Paint over the surface with a paint sprayer. Brush or roller will do the job as well, but spraying the paint will provide you with the best finish.

Final Words

After you have repaired all areas that need attention, go around your property and inspect other planks to see if any of them show signs of damage. If they do, follow the same steps to repair them.

It’s always a good idea to have some extra boards on hand so you can replace any that get damaged in the future. Now that you know how to repair hardie plank siding, it shouldn’t be too difficult for you to take care of small damages as they occur. However, if the damage is extensive, it is best to hire a professional.