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5 Common Signs Of An Improper James Hardie Siding Installation

March 18th, 2022 | 7 min. read

5 Common Signs Of An Improper James Hardie Siding Installation

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So, you’re interested in replacing your home siding with James Hardie siding and want to learn more about how it’s installed. 

Because Hardie siding is on the higher end of siding products for quality and cost, of course, you want to make sure that the outcome of your project is successful to get the most out of your investment. Installation is a crucial part to that success. 

With cost and quality of installation in mind, you want to have all the information you can to ensure that you choose the best contractor for your job and are satisfied with your new siding.

The quality of a Hardie siding installation is just as important as the quality of the product. Although Hardie siding is highly durable, weather-resistant, and long-lasting, it will not perform as it is meant to if not installed correctly. 

This is why understanding Hardie’s best practices for installation and what risks you take by choosing an unqualified installer will help you better understand the importance of a proper installation to select the best contractor for your project. 

Southwest Exteriors has been a siding replacement contractor in San Antonio since 1989. We exclusively offer James Hardie siding, and our expert installers are trained on Hardie’s best practices for all siding products and accessories. 

A siding replacement is a large investment and project to take on. It can get pricey, and many contractors out there will take advantage of homeowners with a "too good to be true" deal. 

What is true, is that anyone can buy and install James Hardie siding. However, not everyone is adequately trained on Hardie’s best practices. Because we’ve been serving the San Antonio area for so long, we have firsthand experience with homeowners that went with what sounded like a great deal and ended up having to replace their siding again in just a few short years.

We want you to be aware of the risks of an improper Hardie siding installation so that you can better understand the importance of choosing the right contractor in your area with credible experience.

This article will outline five common mistakes in James Hardie siding replacements and explain some of the top risks if your Hardie siding is not installed correctly. 

After reading, you will better understand the importance of a proper Hardie siding replacement. You will also be better educated to meet with a contractor, knowing what is needed from your project. 

What are some common signs of an improper James Hardie siding installation? 

Before diving deeper into the risks you and your home take with an improper Hardie siding installation, you first need to know some common mistakes with an inexperienced installer. 

Then, you can better understand the repercussions of these mistakes when we get into those risks later in the article. 

Here, we’ll walk through five specific worst practices that are key signs a contractor did not install your Hardie siding properly. 

1. The siding boards are uneven

One of the most obvious signs Hardie siding was not installed properly is if the siding boards are uneven. 

With traditional horizontal lap siding, Hardie boards are made to be 8.25 in. wide. When installed and layered over one another, 7 in. of the board should be exposed. Anything more or less than 7 in. indicates an improper installation. 

Similarly, the width of boards can be customized. If so, then they must be cut to the desired size. If cut boards are uneven, this is not a quality Hardie replacement. 

How does this affect my Hardie siding and my home? 

While uneven boards are mostly an aesthetic problem, they can also create irregular gaps around your home. If the boards are not installed correctly, uneven gaps can accumulate in seams. 

These seams must be caulk to create a proper seal. If uneven boards create irregular gaps, a contractor may use excess caulk to cover the gaps, although this will not fully protect your home from potential water infiltration. 

2. The siding boards are not nailed properly

A large part of installing Hardie board siding is nailing them properly to the wall. This includes nailing it in the correct part and using the right type of nail. 

If the boards are not nailed properly and in the correct spot, the nail could be visible on the board and could cause damage to the board. 

Similarly, if the wrong nail type is used to nail the siding board, like a headed nail, that nail will be visible on the board. Headless nails are meant to install the Hardie trim boards, so they sink slightly into the board. Then, the nail holes are properly caulked in to smooth out the hole. This is the proper installation for Hardie boards. 

How does this affect my Hardie siding and my home? 

If the wrong nails are used, or cheaper nails are used, they can rust over time when exposed to water. This will also stain your siding boards. 

If the nails are not installed properly on the board, such as if they were installed crooked or not in the right position, they could cause the boards to crack and break. 

3. Excess caulk is used 

Caulking is required where seams meet between a siding, trim, soffit, or fascia board. Caulk is used to create a seal between these boards. This ensures water does not infiltrate into or behind the boards and into your home’s frame. 

A clear sign of an improper Hardie siding installation is if there is excess caulk where there shouldn’t be. This could be around trim, siding, soffit, fascia, or anywhere there is a seam meant to be caulked. 

How does this affect my Hardie siding and my home? 

If the boards were not installed properly and a larger gap was created, some installers will fill that gap with caulk to cover up the large gap. This is not effective in protecting your home and is not a proper installation of the boards or use of the caulk. 

Excess caulk increased the chances of the caulk peeling up, exposing that seam. This poses the threat of water infiltration and rotting to the interior frame of your home. 

4. The wrong type of substrate is used

The substrate is a layer of siding that is installed underneath the actual Hardie boards. For the best installation, Hardie recommends using oriented-strand boarding as substrate. 

This type of substrate, typically referred to as OSB, is made by taking thin and small wood strips and compressing them together into a board. It is a similar material to plywood. 

How does this affect my Hardie siding and my home? 

If the recommended OSB is not used as a substrate for a Hardie siding project, the siding can look bent or bowed. OSB creates an even and flat surface for the Hardie siding. 

Some existing siding on your home can be used as a substrate if the siding is in good condition and will create a sturdy foundation. However, with a complete siding and substrate replacement, other types of substrate used with Hardie boards can make the wall look waved or bowed. 

5. The paint was not applied properly

The final sign that Hardie siding was not installed properly is if the paint was not applied properly. Although the paint is not a Hardie product, it still must be applied properly to complete the project correctly. 

If you hire an inexperienced contractor with Hardie or painting siding, it will reflect in all elements of your project. A botched paint job is a clear indication of an improper installation. 

How does this affect my Hardie siding and my home? 

If the paint is not applied properly, it can appear patchy or spotty in some areas. Also, iIf the paint is not applied to the proper mil or thickness, it will not last as long as it should. 

Darker colors require more coats of paint for the true darkness to come through. If not, the color will fade quicker, and the true dark color will not be prevalent. 

Overall, if the paint is not applied properly and evenly with the best practices, this is a sign of a lower quality contractor, and your Hardie siding project was not installed to the best practices. 

How to ensure your James Hardie siding will be installed correctly

Now that you know five common signs of an improper James Hardie siding installation, you can better understand the potential outcome of your project if you choose the wrong contractor. 

Finding a James Hardie-certified contractor in your area is crucial to the success of your project. Researching and asking the right questions will allow you to filter through contractors and find one educated on Hardie’s best practices and has a track record of success in Hardie installation. 

If you’re looking for a James Hardie certified contractor in your area, check out this link that allows you to find contractors near you that are part of the James Hardie Contractor Alliance Program

When looking for a certified Hardie contractor near you, you must know exactly what to look for. 

This article will outline five qualities for a James Hardie siding contractor. Then, you can feel confident in the contractor you choose and the satisfaction of a proper Hardie siding installation. 

Are you looking for a certified James Hardie installer near San Antonio?

Southwest Exteriors is among three contractors in the San Antonio area that are part of this alliance program. On top of the benefits of having your Hardie siding installed to the highest standards, we also have a certified James Hardie inspector come to your home to make sure we installed everything correctly. 

Not only do we want you not to have to worry about your siding in the future, but we want to provide you with the right resources to be thoroughly educated for your Hardie siding replacement, whether you work with us or not. 

If you’re ready to start your Hardie siding replacement, Southwest Exteriors might be the right contractor for you. 

Schedule your free, in-home consultation with an expert design consultant by filling out this form on our webpage, and get the look you love coming home to!