Is Durock Fireproof? Everything You Need To Know

Fire protection is one of the key concerns when designing and constructing a structure. And to achieve that, you need to pick the right construction materials. 

Well, Durock appears to be pretty popular in this regard. But is Durock fireproof?

Durock is fireproof and non-combustible. It is extremely durable and can resist both fire and water. To be exact, the Durock Cemement Board meets the ASTM E136 and CAN/ULC S114 standards.

However, that’s only a tiny portion of all there’s to it regarding the Durock cement board fire rating. So, if you really want to get to the bottom of the topic, you should keep on reading.

Is Durock Fireproof

What Is Durock?

Before offering an in-depth answer on is Durcok fire rated or not, let’s understand what it actually is. At the core, Durock is a type of cement board. You will find it being used in projects where the environment requires durable and reliable materials.

But that’s not all! Durock is exceptionally versatile. Plus, Durock is flame-resistant and highly weatherproof. That makes it perfect for other uses, such as a base for stucco. 

That said, if you are wondering what makes up Durock, take a look at this list –

  • Cement: The primary component of Durock is cement. It is basically a mixture of clay, limestone, and other minerals.
  • Fiberglass: For reinforcement, Durock utilizes fiberglass. It makes the cement board extremely durable and capable of withstanding harsh conditions.
  • EdgeGuard: In some versions of Durock, you will find EdgeGuard. It is there to prevent spinout and crumbling.

Is Durock Fireproof / Fire-Resistant? – How Is Durock Fire-Rated?

So, is the Durock cement board fireproof? Durock is fireproof and non-combustible. As mentioned earlier, Durock meets the ASTM E136 and CAN/ULC S114 standards. Now, the question is, what do these standards mean?

First of all, the CAN/ULC S114 is a Canadian standard method. It determines the non-combustible nature of building materials. The S114 rating in this standard clarifies that the material is non-combustible.

Is Durock Fireproof

Secondly, there’s the ASTM E136 rating. It is a fire-test-response test that determines the combustibility of building materials. And if a material passes this standard, it is non-combustible and fireproof.

How High of a Temperature Can Durock Withstand?

If you are wondering how much heat Durock can withstand, the ASTM E16 will give you a little idea about it. 

The standard utilizes a furnace for testing materials, exposing the building materials to a temperature of 750 degrees Celsius. So, that means the Durock can easily withstand 1382 degrees Fahrenheit.

How Does Durock Compare With Other Tile Backer Boards?

So, the one big competitor of Durock is Hardiebacker. Let’s take a look at the factors that make Durock stand out from Hardibacker –

Comparison FactorsDurockHardiebacker
Glass MeshYesNo
DurabilityMore durable due to glass meshHas a respectable flexural strength
InstallationDifficult to cut due to glass meshEasier due to having a higher compressive strength
Heat ResistanceMeets the ASTM E136 and CAN/ULC S114 standards.Meets ASTM E136 standard

Glass Mesh

In comparison, Durock cement boards come with glass mesh. The Hardiebacker cement boards do not come with it. That makes Durock boards a little more durable. However, it’s tough to cut these boards because they have glass mesh.


The Durock cement boards are heavier than Hardiebacker. This may seem like a plus point to some. However, the higher weight makes things a little difficult when it comes to the installation process.


Durock cement boards come with EdgeGuard, which enhances the edge performance. As discussed earlier, this property helps the boards to prevent crumbling and spinouts.

So, there are pros and cons for both boards. That means the final decision will depend on your requirements. But can Hardibacker withstand heat? You can get the answer by checking out our dedicated post regarding Hardiebacker here: Is HardieBacker Fireproof? 

Factors that Affect Durock’s Fireproofing Capability

The materials that make Durock are not the only factor determining how fireproof it is. In addition to that, the following factors play a role –


Durock cement boards will not be able to offer good fireproof performance without proper installation. For example, the fire resistance will get compromised if you are not leaving enough gaps or not using the screws.


Even though Durock cement boards are fireproof, they have a threshold. There can be issues if you keep them near flames all the time.

Moreover, you should accompany them with non-combustible building materials such as calcium silicate boards.


The thickness of the board, accompanied by other materials, also plays a role in settling how fire-resistant the setup will be. Assemblies with 1/2-inch cement board alone can offer 1 to 2 hours of fire resistance.

Age and Condition

Over time, Durock boards will deteriorate and will not be able to withstand heat as before. For that reason, you should consider going through the maintenance steps frequently.

Frequently Asked Questions

1. Can Durock be used as a fire barrier?

Durcok is fire-resistant and is non-combustible. That means it can offer fire protection, making it perfect for a barrier.

2. Can Durock be used as a heat shield?

Although Durcok can resist fire, it does not stop heat transfer. But Durock boards can indeed offer some protection from the heat. The

3. Can Durock be used around fireplaces?

Yes, you can use Durock around fireplaces. But make sure you are using it with other non-combustible materials.

4. What is the melting point of Durock?

Durock has a non-applicable melting point. This means that the boards may or may not melt at the same temperature. Instead, it depends on the conjunction materials and the settings of installations.

Final Words

So, is Durock fireproof? In short, Durock is made of fire-resistant materials, which makes it fireproof. However, the overall capacity will depend on the installation, what materials you are using it with, and how you take care of it.