Why Is My James Hardie Siding Failing? 5 Probable Causes

James Hardie is a renowned name across the entire continent, known as North America's best fiber cement siding. This durable, maintenance-free, long-lasting material is known for being a lifelong solution for your home. 

Investing in Hardie siding means investing in the future of your home. 

Because of its reputable history and proven performance, if your Hardie siding is having problems, you wonder why. 

Isn’t this siding supposed to be nearly indestructible? I thought it would never crack. Why are the boards starting to chip? Why is the color looking dull? 

The truth is that if your James Hardie siding is failing, chances are there was either an installation issue or a manufacturing defect. 

Southwest Exteriors has been a trusted San Antonio siding replacement company since 1989, and we exclusively install James Hardie siding because of its proven history.

Our installation teams are professionally trained to follow Hardie's best installation practices, from installing the proper substrate to finishing your paint. 

While our teams are trained on the proper techniques, not all who install James Hardie siding are. Improper installation is the number one cause of failing siding. 

So, let's address some common signs and causes as to why your James Hardie siding may fail due to improper installation or manufacturing defects. 

What Is Causing My James Hardie Siding To Fail? 

If you've noticed your siding cracking, chipping off, or not looking right, you want to know the root cause. 

Once you can diagnose the problem, you can take the right steps to address it correctly. 

Here are five common causes of why your Hardie siding may be failing and signs to look out for. 

1. The wrong substrate was used underneath the siding

When replacing exterior siding, a substrate layer must be installed to act as the underlayer for the siding to be installed atop. 

This substrate layer provides a sturdy and durable foundation for Hardie siding to connect to. 

Hardie siding is meant to be a sheathing material, which means it is not made to be a structural material, such as wood. 

If the wrong substrate or no substrate is used, the siding will ultimately not connect to the home properly. This will cause your Hardie siding to fail much quicker and not last as long as it should. 

At Southwest Exteriors, we use oriented-strand boarding (OSB) as a substrate for James Hardie siding. This substrate is made of wood fibers stranded with added bonding material to create a strong and durable layer for the top siding. 

Sometimes, Hardie siding can be installed on your current siding if it is in good condition and is the right material. But, if Hardie siding is installed on top of the wrong substrate, it will not last. 

Signs This Is Causing Your Hardie Siding To Fail 

If you notice any nails lifting from your siding or boards lifting off your home, this could be a sign the wrong substrate was used in the installation. 

Because the substrate is meant to create the proper bond between Hardie siding and the home, any signs that show your siding is coming off of your home may indicate a substrate issue. 

2. The siding is nailed improperly 

Using the correct nails and nailing the siding boards in the right places is essential to the success of your James Hardie siding. 

If the wrong nails are used, like if they are too short or not strong enough, the siding will not properly nail to the substrate. 

Similarly, if the siding is not nailed in the proper place, such as too closely to the edge of the board, this can cause the siding to crack and chip off. 

Signs This Is Causing Your Hardie Siding To Fail 

If you notice chipping near the edge of your Hardie boards or where the nails on the boards are, this could mean improper nailing is the root cause of your Hardie siding failing. 

If you notice the siding boards lifting from your home, this could be a sign the wrong nails were used. 

3. The siding boards were installed too closely together

Whether you choose traditional lap siding or scalloped shingle siding, there are proper techniques and specifications that must be followed for the siding to be installed correctly and last. 

When these specifications are not followed and the siding is installed improperly, not only will it not look right, but also will not perform as it is made to. 

Siding boards installed too closely together will create unnecessary tightness around your home, meaning any slight foundational movement can cause them to fail. 

Signs This Is Causing Your Hardie Siding To Fail 

If siding boards are installed too closely together, any foundational movement will cause them to buckle and crack. 

Look for unevenness in the siding boards, cracking, or chipping around problem areas, and assess how the siding was installed overall. 

4. Your home has shifted with the foundation

Foundation shifting is an inevitable cause of many failures in your home. It’s an occurrence of Mother Nature and causes cracking and other issues around your home. 

Shifting in your home’s foundation will most likely be noticeable in older homes that have been established for decades as opposed to newer homes. 

As your home moves with the earth’s foundation, it causes cracking in flooring, drywall, and siding. You may also notice your windows and doors are difficult to open if foundation shifting has occurred. 

This problem cannot be avoided and is also typically not covered under many warranties because it is a natural cause. 

Signs This Is Causing Your Hardie Siding To Fail 

If you noticed cracking in your Hardie siding and know it was installed properly by a reputable company, this may be a sign foundation shifting is the culprit. 

If you suspect foundation shifting may be the cause of your cracked siding, look for other signs around your home, such as cracks in the drywall or sticking windows and doors, to be sure. 

5. The siding material has a manufacturing defect

The final reason your James Hardie siding may be failing is if the material has a manufacturing defect. 

Just like with foundation shifting, manufacturing defects in any product are inevitable. While it is unfortunate to deal with, it's always a possible cause when you start to notice problems with those products. 

Luckily, James Hardie’s warranty covers any manufacturing defects on their products as long as they were installed under their best practices. So, if your James Hardie siding isn’t looking right and you can’t diagnose the problem, a manufacturing defect may be the issue. 

Signs This Is Causing Your Hardie Siding To Fail 

If you notice your Hardie siding cracking, peeling, or just looking funky and don’t think it is any of the four above reasons, your siding may have a manufacturing defect. 

If you believe your siding has a manufacturing defect, contact the company that installed your siding to handle warranty claims. 

How To Fix Your James Hardie Siding

Now that you know the five common reasons why your Hardie siding may be failing, you can properly diagnose the problem you are experiencing and take the next steps to correct it. 

It’s important to remember that most problems you may experience with your Hardie siding typically come from installation issues. 

If the siding is not installed properly, you may notice cracking, chipping, or buckling in the siding. If you do not expect the issue to be caused by poor installation, consider foundation shifting or manufacturing defects. 

No matter what problems you notice, contacting the company that installed your siding is the best solution. They should be able to address the issue and provide you with the right fix. 

Problems with anything in your home can cause anxiety and stress. We understand. Knowing what warranty the company you work with and the manufacturer’s warranty offers helps you to understand how you can address any problems with your Hardie siding. 

But we also get that reading through warranty paperwork is not the most fun thing to do. 

Luckily, we’ve broken down Hardie’s warranty for you to easily understand. Read all about it here!