Unveiling the Distinctions: Type X vs. Type C Drywall

7December 2023

Unveiling the Distinctions: Type X vs. Type C Drywall

Discover the critical differences between Type X and Type C drywall to make an informed decision for your next construction project.

Our expert guide delves deep into the properties of these fire-resistant drywall options, ensuring your choices align with safety and efficiency standards.


Understanding Type X Drywall

Core Characteristics

Type X drywall, known for its fire-resistant qualities, is a staple in modern construction. With a standard thickness of 5/8 inches, it incorporates non-combustible glass fibers into its gypsum core, boosting its fire rating to a minimum of one hour.

Special Variants

It’s important to note the existence of Type X Shaftliner drywall, a variant with enhanced fire resistance, typically used in specialized applications like shaft walls and stairwell enclosures.

Delving into Type C Drywall

Advanced Features

Type C drywall, an evolved version of Type X, is available in both 1/2” and 5/8” thicknesses. Its gypsum core is enriched with a higher concentration of glass fibers and vermiculite components, significantly enhancing its fire resistance to a span of 2-4 hours.

Comparative Fire-Rated Drywall Testing

Performance in Fire Tests

In standardized tests conducted by AWCI, Type X, and Type C drywalls were subjected to identical fire conditions.

While standard drywall variants lasted for 12 minutes before cracking, Type X endured for 57 minutes, and Type C impressively surpassed the two-hour mark without failing.

Evaluating the Differences

Cost-Effectiveness and Application

Type C drywall, while being 10% more expensive than Type X, offers superior fire resistance. However, it’s not always the default choice.

Drywall companies often reserve fire-rated boards for specific high-risk areas due to their cost and the varying fire resistance of surrounding structures.

Installation and Orientation

One crucial aspect to consider is that Type C drywall exhibits optimal fire resistance when installed horizontally, making it an excellent choice for ceiling applications. In contrast, its fire rating diminishes when mounted vertically.

Making the Right Choice

Expert Installation and Certification

Fire-resistant drywall only enters the market post-certification by third-party entities.

UL designations provide clear guidelines on the best applications for each drywall type.

We recommend consulting with a professional drywall company to ensure your home’s main structures are adequately fire-resistant.


Frequently Asked Questions

Q: What is the main difference between Type X and Type C drywall?

The main difference lies in their fire-resistance capabilities.

Type C drywall contains more fire-retardant materials than Type X, offering better fire protection.

Q: Can Type X and Type C drywall be used interchangeably?

While they are similar, they shouldn’t be used interchangeably.

Type C is more effective when used horizontally (like for ceilings), whereas Type X is versatile in both vertical and horizontal applications.

Q: Is there a significant cost difference between Type X and Type C drywall?

Yes, Type C drywall is approximately 10% more expensive than Type X, due to its enhanced fire-resistant properties.

Q: Are there specific applications where Type C drywall is preferred?

Type C is particularly preferred for ceilings or areas requiring extended fire resistance due to its superior performance in horizontal installations.

Q: How important is a professional installation for fire-rated drywall?  Professional installation is crucial.

Experts understand the specific applications and orientations for each drywall type to maximize fire resistance and safety.