How fire-resistant is Hardie board?

This blog post will answer the question, “How fire resistant is Hardie board” and cover topics like fire-resistant properties of Hardie board and frequently asked questions related to the topic.

How fire-resistant is Hardie board?

When tested to ASTM E 136, Hardie Board is considered non-combustible and may be used around a fireplace with other non – combustible materials.

Hardie Board Siding: What Is It?

Hardie Board is the most popular fiber concrete siding in the United States and continues to be the best of the best. Fiber cement is a mixture of wood fibers, sand, & water that is used to make concrete. 

As a result, it’s a long-lasting substance that looks like wood. Hardie Board is also climate-engineered, making it a unique fiber cement for use in any part of the nation. However, like with any siding material, it has significant advantages as well as drawbacks. 

What Makes Fiber Cement Fire Resistant?

Because of the manner, it’s created and the ingredients used, James Hardie cement board is fire resistant. Concrete, water, cellulose fibers from plant sources, and silica are used as raw ingredients. 

Silica is inherently fire resistant and may be found in sand, stone, and concrete.

The ingredients are combined together, colored, then pressed into boards. These boards are available in a variety of patterns and textures, and they may be made to resemble other materials, such as wood. As a result, fiber cement is both adaptable and long-lasting.

Fiber cement siding is non-combustible due to the materials used; it will not ignite and hence will not provide fuel to a fire. It also doesn’t bend or melt, making it much more tough and long-lasting. Its inability to catch on fire is a significant benefit.

One thing to remember is that although fiber cement siding does not provide fuel to a fire, it does allow heat to pass through it. That is to say, the siding does not catch on fire and delays the fire from spreading, but it does not stop heat from going through.

If you wish to take additional precautions, you may install internal wallboard that withstands burning for one hour. This, together with other components, may be used to create a one-hour fire-rated installation utilizing James Hardie cement siding.

In the event of a fire, this assembly might save you and the firemen important time. It may offer you more time to exit your house safely and firefighters a greater chance of putting out the fire. 

That is why fiber cement siding is recommended by numerous fire departments around the country. It is the first line of protection against fire in your house.

You may be eligible for an insurance reduction if you install fiber cement siding. Many house insurance providers provide savings since the siding is non-combustible. 

Simply inquire with your insurance carrier to see if they do, and you may be able to save money while also making your house safer.

Fire Protection and Siding by James Hardie®

Unlike many other materials, James Hardie fiber cement siding, such as HardiePlank®, is very fire resistant. When subjected to an open flame, wood frequently feeds the flames, while vinyl melts almost instantly–but fiber cement does not. 

It also won’t add to a fire’s fuel supply. In fact, as a non-combustible cladding, this siding meets ASTM E136 and is certified by fire departments around the nation.

However, although James HardiePlank siding will not enable fire to enter your house, it will allow heat to pass through. Although it is not 1-hour fire-rated, it is nonetheless classified for use in Warnock Hersey & UL assemblies that are 1-hour fire-rated. 

Siding that has been professionally placed by exterior house contractors and can withstand fire for an hour is very useful for homeowners who want to protect themselves & their property securely in the event of an emergency.

Are James Hardie materials considered masonry?

Masonry is defined as a kind of structure made up of stone, brick, cement, gypsum, tiles, glass block, or other materials put up unit by unit & set in mortar by the Uniform Building Code. 

Despite the fact that James Hardie products, like other masonry materials, are erected using nails, they are essentially made of concrete and have performance qualities comparable to brick, stucco, & stone. 

Fire, dampness, and insect resistance are among these properties. For these reasons, several cities include fiber-cement in their masonry definitions.

Is it possible to use James Hardie materials around a brick fireplace?

Yes, when tested to ASTM E 136, HardieBacker Cement Board is considered non-combustible and may be used around a chimney with other noncombustible materials. 

This does not imply that HardieBacker 1/4″ may be used to minimize clearances to flammable construction components. 

Even if they are covered by noncombustible materials, clearances to combustible building elements must be observed; please consult your local building & fire code for precise combustible clearance specifications surrounding brick fireplaces.

The Advantages of Hardie Board

There’s a reason why Hardie siding secures millions of houses throughout the United States. The advantages of this housing material are many. It provides advantages that many other types of siding just cannot.

  • Durability
  • Longevity
  • Color Durability
  • Variety and Attractiveness
  • Eco-Friendly
  • Resistance to Storms

I will now elaborate on the guidance given above.


The durability of the Hardie Board is perhaps its most well-known and desired feature. It can survive practically every element or weather condition because of its fiber cement construction. Its weather tolerance allows it to blend in with practically any environment.

Hardie siding is water-resistant, fire-resistant, pest and bug resistant, which means it will not only survive longer but will also protect the inside of your house from warping & breaking.


Hardie Board siding is not just long-lasting but also very durable. It has a longer life expectancy than practically any other siding material. Fiber cement is impervious to decay and does not bend or warp. 

A 30- to 50-year guarantee is also included with James Hardie products. Your siding will have a warranty if installed and cared for properly, or it may never need to be replaced at all.

Color Durability

Unlike wood siding, which requires refinishing every few years, Hardie Board requires fewer coats of paint throughout its lifetime. 

James Hardie® employs baked-on ColorPlus® technology to cover its products, which keeps colors locked in and vivid for longer. It doesn’t fade and isn’t as prone to scratch as other materials.

Variety and Attractiveness

Hardie siding is a lovely option for siding. It features grooves & grains that simulate the appearance of wood. 

This gives a house the appeal of genuine wood without time-consuming maintenance. It also offers a wide range of design alternatives, including smooth and rough-textured vertical and horizontal panels, as well as shingles and stucco. 

The variety of alternatives available enables homeowners to create the style they want for their houses.


For the 6th year in a row, Green Builder Media’s annual Readers’ Choice poll voted James Hardie the “Greenest Siding Brand.” This is because James Hardie’s products are made using sustainable techniques and natural components. 

Resistance to Storms

Siding may be damaged by strong winds and hail. Hardie Board siding, on the other hand, is more resistant to strong impacts because of the composition & strength of fiber cement. 

It will not fracture or dent, and it is one of the most effective methods to protect the outside of your house against storm damage.

Cons of Hardie Board

Hardie Board siding has a far shorter list of disadvantages than advantages. There isn’t much to complain about. However, there are a few things to consider before deciding on Hardie siding for your house.

  • Difficult to Install
  • Excessive labor costs
  • For Years to Come, a Low-Maintenance Exterior

I will now elaborate on the guidance given above.

Difficult to Install

Hardie Board installation might take longer and be more complex than other materials due to the composition of fiber cement siding. Because fiber cement is heavier than vinyl, it necessitates a more exact installation. 

And only specialists who have been educated to deal with the siding in line with its guarantees should install it.

You should not try repairs on your own. Poor setup and errors committed throughout the repair procedure might invalidate your product’s warranty and create future difficulties.

Excessive labor costs

Hardie Board siding may be more expensive to install than other types of siding due to its complicated installation procedure. For a proper installation, the procedure takes a little longer & requires a cleverer eye and expertise.

Never try to put up this siding on your own. Hiring a Hardie-trained expert might end up costing you more in the long run than the original labor expense. 

Look for a Hardie Recommended Contractor when hiring a contractor. They carry James Hardiestamp ®’s certification, allowing you to determine the degree of installation quality you’re getting.

For Years to Come, a Low-Maintenance Exterior

Don’t waste your time & expense on low-quality, difficult-to-maintain siding. The advantages of Hardie siding are just a phone call away. Hardie Board is installed by our skilled crew, which ensures flawless and easy operation.

Frequently Asked Questions(FAQs), “How fire resistant is Hardie board?”

Are Hardie boards resistant against fire?

Protection Against Fire

When subjected to a direct flame, Hardie siding will not burn, nor will it lead to the spread of a fire. Many insurance companies provide a discount because James Hardie brand materials are non-combustible.

What types of home siding are fire-resistant?

Fiber cement siding has a fire-resistance that can fulfill the most stringent fire- & weather-protection regulations, and it is often suggested above other siding materials because of its longevity, even in the most extreme situations.

Is Hardie board suitable for use as a heat shield?

Hardi cement board is a low-cost option that may be used to provide an efficient heat shield in a variety of applications. 

Hardie cement board is also intended to have porcelain, ceramic, or stone tiles placed over it after it has been installed to cover & beautify the heat shield.

Is it possible to put cement board around a fireplace?

Hardiebacker Applied to Fireplaces

It can’t be replaced, and it shouldn’t be hidden by more combustible things. However, cement boards, such as Hardie board, may be used in places like the mantel & fireplace surround.

What do you hang behind the wood stove on the wall?

Masonry veneer imitation panels are a popular technique to shield the wall behind a wood burner while also providing a background for your stove. 

A frequent material used behind a wood stove is stone or brick. These panels serve to make a room’s focal point more prominent.

What is the definition of a non-combustible board?

Building materials that are non-combustible do not ignite or burn when exposed to predicted amounts of fire or heat. Brick masonry, concrete blocks, tough backer board, metal, and some kinds of glass are examples of non-combustible materials.

Durock vs. Hardibacker: which is better?

HardieBacker is the preferred material for countertops & tiles. Durock is overly abrasive, causing vinyl, ceramic, and enamel to be damaged.

HardieBacker is the better option since it does not include any course materials. It comes with a guarantee that covers vinyl tile applications.

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