Fire Ratings for Different Drywall Types

With winter nipping at our heels, the rate of house fires will soon be on the rise as people try to stay warm during the cold depths of winter. With most American homes using drywall for their interior wall finish, what happens to drywall in a house fire and what's the difference between the different types? In this post, we'll talk about the differences in fire ratings for different drywall types as well as what other areas should be addressed so the fire resistance actually lasts that long.

What Makes Fire-Rated Drywall Different from Regular Drywall?

Regular drywall helps slow down fires because it has a 21% water content, which is released as steam during a fire, slowing down the transference of heat from one side of the wall to the other. Its failure point is when the drywall crumbles and the fire is allowed to continue spreading. By comparison, fire-rated drywall contains glass fibers and other materials that help the panel continue to conserve structural integrity for a longer period of time. Additional levels of fire-rated drywall provide additional fibers and materials to help retard the spread of fire further, but often costs more. For this reason, it's usually reserved for high-risk areas such as welding shops, restaurants and other areas where there is a much higher than usual risk of fire.

Fire Ratings for Different Fire Types

Fire Fighter Fighting a FireStandard 1/2" drywall provides about a half hour of fire resistance. It is commonly used in most areas of the home because it provides some basic protection at a lower cost. By comparison, 5/8" fire-rated drywall, also referred to as Type X, has a one hour fire rating and is typically installed between the garage and the rest of the home in a residential setting. Why? Because the chemicals and combustibles that are often stored in the garage creates a zone where fires are more likely to occur. It also has some sound-deadening effects, if loud is the only setting your household operates under. For specialty applications such as studios with kilns, forges or similar hot spots, or for homeowners who want a little more assurance that they can get everyone out and to safety, there are also two, three and four hour fire-rated drywall panels available, though they may require a special order to obtain them.

Other Factors That Can Affect Your Home's Performance During a Fire

Star Sprinkler AlarmThough fire-rated drywall can help provide some protection against a fire, it's only as effective at controlling fire as the other components in your system. What components, you ask? Do you have wood or steel studs holding the drywall in place? What about the interior doors in your home? A standard hollow-core door provides virtually no protection against the spread of fire when compared to a solid fire door that gives your family more time to get away. Do you have wood or tile flooring? Does your home have stairs that can create a thermal chimney effect, allowing the fire to spread more rapidly? There are many other considerations to think about when making your home safe from fire.

When it comes to house fires, an ounce of prevention is worth a pound of cure. Test your smoke and carbon monoxide detectors, sweep your chimney if you use wood heat, use seasoned firewood and make an evacuation plan for everyone to get out safely. Once you have a plan in place, drill it - preferably better than "The Office" did recently. With house fires on the rise during the winter, it's a great time to finish that project you've been waiting on with fire-rated drywall to give you a little more peace of mind. Download our Firestop Product Guide to start protecting your home and family today.

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Wallboard Supply Company is a third generation, family run business that has been serving New England's building needs since 1970. Bob Filion started the company with a commitment to provide quality drywall and finishing products with unmatched customer service. The company has grown over the years, expanding its' product range, but never wavering from its' core values.