Don't Let Your James Hardie Siding Fail: What Every Homeowner Needs to Know

So you've chosen James Hardie siding for your home, a top-tier product known for its beauty, strength, and durability. You've made a great choice! But what happens when that premium siding starts to fail just a decade after installation? Unfortunately, it's a common issue we see at Pro Exteriors, and it's almost always due to improper installation, not a faulty product.

Original installers did not locate wall studs prior to installing the siding.

In a recent episode of our podcast, the "You Ask the Pros Answer," we broke down a real-life repair job to show you exactly what to look for and how to ensure your James Hardie siding is installed the right way.

The Warning Signs of Bad Siding Installation

We recently got a call from a homeowner with an attached condo that was about to be repainted. He'd noticed some troubling signs with his James Hardie siding, including water infiltration and interior damage. When we went out to the site, we found some major red flags.

1. Improper Nailing: The #1 Offender 🤕

The most significant issue we found was a lack of proper nailing. James Hardie siding is heavy, and it needs to be nailed into the studs for structural support. We discovered that a shocking 10-15% of the nails on this Selbyville, Delaware, house were actually in a stud. The rest were just in the plywood sheathing, a "happy accident" at best.

When siding isn't nailed into a stud, it can vibrate and shift over time, leading to:

• Siding misalignment: Boards can fall out of place.

• Nail failure: The nails can either back out of the plywood or pull right through the siding itself, leaving it unsupported.

2. Poorly Spaced Joints 📏

James Hardie butt joints—where two pieces of siding meet—should align with the studs, typically at 16 or 24 inches on center. In this house, the joints were randomly spaced at 25, 24, and 26 inches. This isn't just a sign of sloppiness; it means the installers weren't even attempting to find and nail into the studs, which is crucial for a strong, long-lasting installation.

3. The Wrong Flashing Material 📄

To prevent water infiltration, the butt joints need to be protected with a flashing material behind them. A lot of installers use standard 15-weight tar paper, but this is a huge mistake. Tar paper breaks down when exposed to UV rays, which can happen as the siding naturally expands and contracts. This leaves the joint completely unprotected and vulnerable to water damage.

How to Install James Hardie Siding the Right Way ✅

A proper James Hardie siding installation is a meticulous process that follows the manufacturer's strict guidelines. Here's a quick look at how we do it at Pro Exteriors:

• Proper Weather Barrier: We start by installing a proper house wrap, like Kimberly-Clark Block-It, that is surfactant resistant and creates a crucial air gap behind the siding to prevent moisture buildup.

• Stud Marking: After the house wrap is up, we mark all the studs with a level line. This ensures every nail hits a structural member and the siding is perfectly aligned as we move up the wall.

• Touch-Up Paint: Every cut edge of the siding must be primed with matching paint to prevent the fiber cement from absorbing moisture.

• Consistent Lap Tools: We use special tools to ensure every single row of siding has a consistent reveal. We check our work with a level every few rows to prevent any crooked lines from forming over a long wall.

• Correct Flashing: We use GAF’s Ice and Water Shield cut into strips to flash every butt joint. This material is designed to last as long as the siding itself, protecting your home for decades.

• Leaving the Right Gaps: We leave a crucial 1/4-inch gap at horizontal trims (like above windows) and a caulk gap at all other penetrations. This allows the siding to expand and contract naturally.

Why James Hardie is Worth It (When Done Right)

So why go through all this trouble? Because when it's installed correctly, James Hardie siding is an incredible product. It's beautiful, strong, and can withstand a beating from baseballs to golf balls. It's insect-resistant, won't rot like wood, and has a Class A fire rating, making it a perfect choice for areas prone to wildfires. The manufacturer even backs it with a fantastic warranty—but that warranty is void if the siding isn't installed to their specifications.

This is why choosing the right contractor is so important. A professional installer like Pro Exteriors will ensure your siding is installed correctly, preserving your warranty and protecting your investment for years to come.

Want to learn more? Check out our special 20th-Anniversary Bundle! We're giving away free stainless steel micro-mesh gutter guards with any roofing or siding replacement project. No more cleaning out your gutters!

Ready to get started on your exterior project? Visit AskProExteriors.com to find out more.