How to Install Hardie Board Siding

By Amanda Lutz Updated May 13, 2024

Hardie board siding is a popular option for durable, beautiful siding that can protect your home in the long term. This damage-resistant material can be manufactured to fit any design aesthetic. But because Hardie board is pricier than budget-friendly options, such as vinyl siding, many homeowners choose to save money with do-it-yourself (DIY) installation.

Installing your own siding can be a great home improvement project if you have experience repairing siding or making home renovations. In this step-by-step guide, we’ll explain the benefits of Hardie board siding, the tools and materials you’ll need, and how to install it.

Benefits of Hardie Board Siding

Replacing your home’s siding is a big decision, so it’s important to evaluate the potential siding material before you buy it. Consider factors such as initial cost, ongoing maintenance, durability, and aesthetics. You should also consider your plans for your home. For example, do you plan to sell it soon, or will you live in it for many years to come?

Hardie board siding offers these benefits to homeowners:

However, there are some drawbacks to consider. Hardie board can stretch your budget, with pricing averages on HomeGuide coming out to $6 to $15 per square foot of siding. It’s also bulky and heavy, which is great for durability but can make DIY installation challenging. The heft can make it hard to carry, measure accurately, or cut without the right tools.

Safety Considerations

Every DIY home improvement project requires safety precautions, and installing your own siding is no exception. Hardie boards are heavy, so always only pick up one or two panels at a time, and lift by engaging your legs rather than your back. Installing boards high up on your exterior walls can be dangerous because of how heavy they are, so always have someone on a second ladder to help support the weight.

Cutting the Hardie board panels can also be hazardous. Wear eye protection and a mask while cutting the panels to minimize your exposure to the dust. We also recommend wearing gloves to avoid cutting your hands on sharp edges or debris.

Some best practices for avoiding common accidents include the following:

Following these safety precautions can help you complete the project with a lower risk of accidents and injuries.

Tools and Materials

Installing Hardie board siding is an advanced DIY project. Not only is it challenging, but also it requires a lot of specialized tools and materials. Before deciding to do the project yourself, have these tools already.



Gather these materials, and prepare them for your project before beginning the installation process. 

Step-by-Step Installation Guide

You can install your Hardie board in seven steps, but expect the entire project to take around seven days once all your materials have arrived and acclimated. Follow these installation instructions:

Step 1: Remove Old Siding and Install New Boards and Moisture Barriers

Start by removing the old siding materials and placing them in a pile for disposal. Wear protective gear during this process to avoid cutting your hands or breathing in dust. Carefully uninstall the panels to minimize damage to the underlying sheathing material.

Once you have removed the panels, inspect the underlying materials for pest damage, rot, or moisture. Replace any dirty insulation or add thicker insulation based on your climate.

If your home doesn’t have boards or other sheathing, you must install them before adding the siding. Install plywood or OSB across the entire exterior cavity, and nail it in place against the studs and framing.

Next, install the moisture barrier, which is a house wrap made of plastic sheeting. Cover the entire surface, and ensure the edges overlap so there’s no gap risk. Also, install any flashing that the Hardie board siding will partially cover.

Step 2: Cut Fiber Cement Siding Boards

There are two different strategies for cutting siding boards: You can cut everything at the start, or cut as you go. If you have two or more people on the project, one person can cut boards as the others install them. However, if you’re preparing the materials while waiting for someone to join you, we recommend cutting the boards all at once.

Measure the length of the exterior section you’re covering, and cut the boards to fit that size. It’s important to establish a pattern so the ends of the boards don’t line up to create a harsh vertical edge. Instead, stagger the cuts for a more uniform, professional finish. This will make cutting and measuring more complex, but it improves the final look.

As you cut the boards, organize them into stacks for fast, easy installation.

Step 3: Build the Corners

Start by pre-assembling the corner pieces. First, count your home’s outside corners. For each corner, set the long narrow edge of one board against the top of another board’s face and nail the boards in place to create a corner trim. Set the corner in place against your home’s exterior sheathing.

Starting at the bottom, nail both sides of the corner in place at least once per 16 inches. Finish nailing approximately 1/25 inch from the top. Repeat this process for all the corners.

Step 4: Install the Trim

Before you install the horizontal boards, install the trim. These pieces will go around your doors, walls, flashing, and other fixtures. You’ll have clean lines for the horizontal panels to butt against by installing the trim first.

Measure and cut each trim piece in typical styles. You can either cut diagonal joining edges or, more commonly, have the horizontal lengths of trim be long enough to cap the vertical trims. Nail them in place against the studs, and make sure they’re level.

Step 5: Lay the Starter Strips

You would typically install horizontal Hardie board siding by starting at the bottom and going up. The bottom row will start with a starter strip slightly overhanging the sheathing onto your foundation. Install it with 6 inches of clearance at the bottom. This strip should be 1.25 inches wide. 

Install it by driving nails into place near the top edge, and make sure the board is at a slight angle—with the bottom edge protruding further forward than the top edge—to match the angle of the future siding.

Step 6: Install Fiber Cement Siding

Now, you can start installing your siding panels. Starting from the bottom starter strip, ensure each panel is completely level along the length. There will be a slight angle as each panel will overhang the panel below. Nail each panel in place approximately 1 inch from the top of the panel below it and at least once every 24 inches. After nailing each panel, check to ensure it’s level. 

Continue this process until you have installed all the panels up to the roofing. Also, step back every few rows to ensure the cut joints are staggered and the wall looks uniform. As you put the panels in place against the trim, make sure it’s moderately flush and touching as a butt joint. However, there should be an approximately 1/8-inch gap between the horizontal cement board edges and the corner trim.

Step 7: Caulk the Seams

This final step seals the edges so moisture and pests can’t get inside. Choose a permanently flexible caulk that won’t crack over time, and use it to seal all the edges, especially around the trim and flashing.

As the caulk dries, you can clean up your materials and check for gaps or missed edges.

When to Call a Professional

While homeowners can install Hardie board siding themselves, they may also choose to hire certified professionals in Hardie board products and installation methods. You could actually invalidate the manufacturer’s warranty if a certified contractor didn’t properly install the siding.

We recommend hiring a professional if you’re uncomfortable completing all the steps yourself. If you have a large home with a complex exterior layout, such as a breakfast nook protrusion or many windows, consider hiring contractors to complete the work.

Call at least three contractors if you decide to hire a professional. Confirm that they are certified in Hardie board products, get estimates and quotes for the work, and check their online reviews to ensure they provide excellent service.

Our Recommendation

Hardie board siding is an excellent investment for your home. It’s a beautiful, long-lasting material that you can enjoy for decades. If you’re familiar with big home improvement projects, you can try installing them yourself. However, if you haven’t worked with James Hardie siding before or are worried about the project’s complexity, hire reputable local contractors with experience in certified Hardie installation methods.

Hardie Board Siding Installation FAQ

What is the best way to attach Hardie siding?

The best way to attach Hardie siding is to use the blind nailing technique. Install the nails near the top of the boards, where they’ll be covered by the row above. It’s best to use galvanized siding nails or stainless steel nails.

What do you put under Hardie siding?

You can put plywood or OSB panels and a home wrap under Hardie siding. This protects your home from moisture and pests and creates more stability when attaching the siding.

How do you fasten Hardie board siding?

Fasten Hardie board siding by using a pneumatic nail gun with galvanized or stainless steel nails as the fasteners. The recommended length between the nails differs depending on whether the panel is siding, trim, or a corner joint.

Do you nail or screw Hardie board?

You nail the Hardie board into place. Use a pneumatic nail gun to complete the process more quickly.

How long does Hardie board siding last?

Hardie board siding can last 50 years or even longer. The manufacturer’s warranty covers 30 years, which is longer than that of other siding material warranties.