Fiber Cement Siding Repair 101

Fiber cement siding is a popular material for homeowners who want durability, maintenance-free properties, and the look of cedar for their exterior material. Plus, the siding also has fantastic insulating properties that offer your home protection from heat loss, noise reduction from breezes, and moisture resistance. However, like with any type of siding, fiber cement will succumb to damage over time and can start to show signs of wear. If the damage worsens, you’ll find small cracks in the paint surface or a few larger ones.

Sometimes these tiny cracks go unnoticed until you catch a glimpse of daylight through them and see what’s happening inside your home. Other times they are obvious enough to warrant a repair. The good news is that most repairs aren’t difficult or expensive, and depending on the severity of your damage, some repairs may only take you a few minutes. So, if you need to do a full repair or even a quick patch-up, here’s what you’re going to need to know when it comes to fiber cement siding repair!

What Can Go Wrong With Fiber Cement?

There is always going to be some type of variable where fiber cement siding is going to need to require repairs. For the most part, you can expect this to be due to faulty installation, such as poor nailing, gaps, unevenness, or even a lack of backer flashing. While poor installation can affect this, you can still have good installation, and something can still go wrong. 

This can include extreme weather, extreme temperatures, water damage to the underlayment, rodents, pests, and even collisions. Sometimes the damage itself is simply cosmetic, but depending on what happened, there may be a chance that everything needs to be replaced.

What to Expect When You Repair Fiber Cement Siding

When it comes to fiber cement siding, there are multiple reasons why something may have happened to it. With that said, there are also multiple ways to fix it too. Overall, depending on your experience and the severity of the fiber cement siding, it’s best to use your intuition. If something you’re not familiar with or think goes far beyond your expertise as a home repair person, make sure to hire a professional. While a professional may be costly, they’re going to be able to repair your fiber cement siding the right way.

Repairing Scratches on Fiber Cement Siding

For the most part, scratches on your fiber cement siding are going to be mostly cosmetic; unless it’s a very deep scratch that could penetrate the underlying, you shouldn’t have anything to worry about. However, if you want to repair the scratches, all you’ll need to do is fill them with an exterior filler, sand it, add a spot primer, and then paint the whole piece of siding, so everything looks even.

Repairs to Cracks in Fiber Cement Siding

Cracks are not only a cosmetic issue to siding, but they can put the house in danger. Moisture, especially rain and condensation, can get into the cracks and make it to the underlying. Fiber cement takes a long time to dry, which means that you can expect mold and mildew to grow. In order to prevent any of this, the moment you see a crack, you’re going to have to seal it up. So here’s what you can expect to do:

• Apply joint compound over the damaged area and then sand it smooth.

• Use liquid nails to fill in the crack or any other type of exterior filler; afterward, paint over it.

• If you have access from the inside (which shouldn’t be too likely), you can use a putty knife to pull out the loose pieces of siding and repair them with joint compound.

Alternatively, you can always hire a professional; if you’ve had a crack for a long period of time, this could mean that moisture has already been trapped. Hiring a professional will give them the opportunity to check to see if anything can be done to repair the underlying and the fiber cement siding too.

Replacing a Damaged Panel on Fiber Cement Siding

The process for replacing a damaged panel on fiber cement siding is simple and can be completed in less than an hour.

1. Clean all surfaces of the damaged area with a glass cleaner or wood cleaner.

2. Remove screws and nails from the back of the old panel and any remaining nails from the bottom of the threshold so you’re not damaging your new panel by hitting them with a hammer or screwdriver.

3. Carefully slide the new panel into place and secure it to the house using new screws and nails, making sure that the edges align properly before securing them, too, with a hammer.

4. Fill any cracks and holes in your new panel using caulk, expanding foam, or spackling compound to make it watertight again.

5. Remove any leftover screws from your old panel, replace them on your new one, and then reinstall it on your home’s exterior wall surface.

It’s vital to keep in mind that since this does involve removing and replacing a panel, it means that the installation needs to be perfect. Either follow the manufacturer’s instructions or, instead, reach out to an experienced contractor to do the job.

Stucco Repair for Fiber Cement Siding

The most common repair for fiber cement siding is stucco. If you live in an area that doesn’t have much wind, the repairs are easy; but if you live in a region with high winds, then repairing your fiber cement siding may be more difficult. To fix your fiber cement siding, you will need to scrape off the old paint surface and clean the surface of any dirt or debris. 

Then use a trowel (or a small piece of plywood) to apply a new layer of paint to your siding. If necessary, add a second coat on top of the first one to create a thicker finish. You’ll probably cover up any cracks with tuckpointing before painting so that they don’t show through when your paint dries.

Bottom Line

If fiber cement siding is taken care of, it can last up to 60 years. It’s a highly durable product, but you need to keep in mind that if this was installed into the home 25 to 30 years ago, then it’s going to be vulnerable compared to fiber cement siding that was installed one year ago. For the most part, having a maintenance schedule and eliminating the underlying problem (such as water damage) before making the repairs can help you drastically. 

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