As any homeowner knows, drywall is an essential part of the house. It creates interior walls and ceilings and provides a fire-resistant barrier between rooms. But many people don’t realize that drywall can still catch fire.
Drywall has a flashpoint of 176 degrees Fahrenheit and will catch fire even if it has fire-resistant properties. Some have a fire rating of 30 minutes, which means they will likely catch fire after 30 minutes of exposure to fire. In contrast, others have a 1-hour fire rating.
There’s no simple answer to the question of whether or not drywall is fire resistant. While drywall itself won’t catch on fire easily, it can be damaged by exposure to heat, resulting in a loss of fire resistance.
Is Drywall Fire Resistant?
Yes, drywall is fire resistant to some degree. Because Drywall is partly made of gypsum, a non-flammable mineral that is pressed between two thick sheets, this material slows down fire. However, some drywalls are better at slowing down fire than others.
A perfect example is Type X drywall which has a 5/8 inch thickness. This type of drywall is denser than regular drywall and takes a long time for the fire to degrade the material, which is also why you would you this type of Drywall mostly around fireplaces. It’s also known as fire-resistant Drywall.
Does drywall catch fire and burn?
Yes, drywall can catch fire and burn. Drywall may have fire-resistant properties, but it eventually still catches fire. The good part is that it takes time. Some may take longer than others, but drywall will definitely burn.
Although it’s commonly used for limiting fires in buildings, this fire barrier is by no means immune from fires.
Does Drywall Catch On Fire Easily?
Drywall does not catch fire easily; if it does, it burns very slowly, at least the gypsum part. Since it also consists of two thin layers of paper in between, which burns much faster. Unless it reaches this temperature point, it won’t burn. Drywall is a combination of sheets, water, and gypsum, and the thicker the sheets, the higher the concentration of gypsum. All these materials combine to limit flammability.
Also, note that the fire resistance of the drywall depends on the fire rating; that is why some drywalls are better at handling fire than others. For instance, ½-inch thick drywall has a 30 minutes fire rating; 5/8-inch drywall has a 1-hour fire rating, while ¾-inch drywall has a 2 hours fire rating.
As you can see, they all do not catch fire easily and have different burn rates due to their fire rating. So if you want drywall with a slower burn rate, consider going for a thicker sheet.
What Is The Combustion Temperature Of Drywall?
Drywall has a flashpoint of 176 degrees Fahrenheit. This is because paper ignites at the same temperature level. However, for drywall to catch fire, the moisture inside the gypsum coat must evaporate first, requiring more than 176 degrees Fahrenheit heat. Once it exceeds that temperature, it will combust.
It is also important to note that all drywalls don’t have the same combustion temperature. Temperature varies depending on the quality of the sheet and the extra additives mixed into the gypsum material. For instance, some drywalls have fiberglass, which has fire properties. Any drywall with fiberglass deposits added to the gypsum will have a much higher combustion temperature above 176 degrees Fahrenheit and a slower burn rate. Good examples of this type of drywall are Type X and Type C drywall.
Are All Drywalls Fire Resistant?
All drywalls are in some way fire resistant, but some have a higher fire rating than others, which we already established throughout this article to some degree. Drywalls contain natural fire-resistant materials largely because they contain a 21% water ratio. In the event of a fire, the water deposit is released gradually as steam to slow down heat transfer and the fire from one side of the wall to the other.
Although regular Drywalls are fire resistant, they crumble in a matter of minutes because of the limited water deposit. After a short time, the sheets will ignite, and the fire will spread.
However, high-fire-rated Drywalls don’t catch fire easily. Fire Rated drywalls are more durable than regular drywalls because they contain gypsum, fiberglass, and other materials that increase fire resistance for much longer than regular drywall. Some examples below
Type X: A Type X drywall is a drywall with gypsum and non-combustible glass fiber. This material increases fire resistance with a minimum fire rating of at least one hour. This type of drywall is commonly installed in stair walls and shaft walls.
Type C: Another very good example of fire-resistant drywall is Type C drywall. This one is more durable than Type X, with more fiberglass and vermiculite materials. It has a fire rating of between 2-4 hours with varying levels of thickness. Type C drywalls are the highest-rated fire-resistant drywalls. Although they are more expensive, they keep the fire at bay in case of an outbreak.
FAQs:
Is Drywall Compound Fire-resistant?
Yes, the drywall compound is fire resistant. All drywalls have this compound, but not all of them have a high fire rating. Regular drywall compounds have limited fire ratings, unlike Type X drywall compounds with additional materials besides the gypsum compound, such as fiberglass. Fiberglass is a highly inflammable material, so drywall with 21% water and fiberglass compound will restrict fire spread. Many drywall compounds are used in thick drywall sheets like the 5/8 inch sizes.
Does Gypsum Boards Catch Fire?
Yes, a gypsum board will catch fire only if it is exposed to it for a significant time. Gypsum contains 21% water which serves as a barrier against fire. When exposed to fire, the water slowly evaporates with the steam quelling the spread of fire and reducing heat transmission.
Is Regular Drywall Fire Rated?
No, regular drywall is not fire-rated. The only Fire-rated Drywall is the Type X drywall. You can recognize it by checking the back of each board, which should have UL/ULC Marking printed.