Are Drywall Walls Fire Retardant?
Yes and not. A lot depends on how the drywall combines with other structural and material choices. As for the drywall, although the paper is flammable, the gypsum itself is not, and still can be part of a safe, fire-unfriendly wall structure.
Typical drywall has a thickness of 0.5 inches, and it’s made of gypsum between some thick paper. The paper is (obviously) flammable, but the gypsum is not.
Drywall is also commonly known as sheet rock, gypsum board, and plaster board. Gypsum is calcium sulfate dihydrate. It’s used in lots of applications including blackboard chalk.
But there are lots of different types of drywall. There is moisture-resistant drywall used in bathrooms, eco-friendly drywall, and type X and type C drywall that both have a better fire rating than most.
Type X drywall
Type X drywall is thicker than normal half-inch drywall, and glass fibers are mixed with the gypsum which gives the drywall more structural integrity in the case of fire. Another benefit of this type of drywall is that it offers better soundproofing than regular drywall.
Type C drywall
Type C drywall is somewhat more fire retardant than type X. Type C drywall contains more glass and also contains vermiculite—another non-flammable material.
Vermiculite is a light-weight phyllosilicate mineral that is commonly used in fire- proofing materials. Sometimes vermiculite contains asbestos, but today, vermiculite is usually tested for asbestos early in its mining or production—and the vermiculite that contains asbestos is not typically used. You may have noticed vermiculite at your local garden center where it’s often used to improve the quality of and aerate garden soil. (It’s sold in big bags.)
Just using type X or type C drywall everywhere will not fireproof a home. Fire spreads in lots of ways, and you would have to make some other structural and material changes if your goal was to make a structure as fire-unfriendly as possible. Choosing the best drywall material for a building project depends on a lot of factors.
Drywall is our business, and we’ve been working with drywall for almost 90 years (drywall has existed for about 130 years). Contact us if you would like some help with your drywall project.
Turner Bros Contractors Ltd. has been providing steel-stud framing, drywall, and acoustic ceiling services for residential and commercial applications in the Vancouver area since 1932. The company is family-run with four generations of the family represented in the business.
If you have any questions about this article or would like to talk to us about your residential or commercial project, please call us at (604) 532-1991 or email us at firstname.lastname@example.org.