- Gypsum drywall (Sheetrock) fire protection
- Risks to firearms caused by Gypsum drywall
- Gypsum drywall fire protection limitations
- Final thought
In comparison with other types of safes, gun safes are differently. Fireproofing in gun safes is also different. Thus, having an understanding of gun safe construction and the gun safe’s fireproofing construction process will help you a lot in figuring out your needs.
Gypsum drywall (Sheetrock) is for fireproofing in gun safes. In this article, we’ll find out together the reasons behind it and see how it helps protect your gun safe against during a home fire.
Gypsum drywall (Sheetrock) fire protection
In the construction industry, Gypsum drywall is like Sheetrock which is a trademark of USG.
However, in gun safe construction, gun safe manufacturers refer to Gypsum as fireboard, fibreboard, and firewall. Gypsum drywall, in commercial and residential construction, is used as wallboard over studs.
Gypsum drywall is also for slowing down the fire from spreading in some construction applications.
What is Gypsum Drywall?
Gypsum is CaSO4.2H2O with the chemical name: Hydrous Calcium Sulphate. Water occupies almost 50% of the total weight representing 20.9% of the substance chemically.
In the event of a fire, when you heat the Gypsum above 212o, the water will break its chemical bonds and starts to boil as water vapor. This process is calcination. It’s a phase change where a solid or liquid is converted to a gas. In this case, a solid is converted to steam.
Converting water to steam is an endothermic reaction. In this reaction, a certain amount of heat will be absorbed for the reaction to happen. That means you need to heat water to create steam.
The amount of heat needed for an endothermic reaction varies from chemical to chemical.
For example, they use the Latent Heat of Vaporization in air conditioners. The air conditioner manufacturers will compress and cool the refrigerant to a liquid which is stored in the condenser. Then, you will put the condenser outside of the house. When the air conditioner works, the refrigerant changes phases to a cool gas in the evaporator coil.
How does Gypsum drywall work?
Now let’s go back to the topic of gun safes. When a fire happens, the Gypsum will absorb heat from the fire and convert water into it to steam, keeping the gun safe’s interior cool.
Well-constructed gun safes will be able to maintain its sealing in the event of a fire. So when steam is let out, it will add a small pressure to the gun safe’s interior. It will help prevent hot gasses and smoke from getting inside. This is a very nice bonus. When all the water is in conversion to steam, the gun safe’s interior will remain around 250o to 300o and the internal humidity is at a high level.
Keep in mind that the water, which will eventually be converted to steam, is part of Gypsum molecules. Once all the water is gone, what’s left isn’t Gypsum anymore, but a different chemical that is CaSO4 with the chemical name: Anhydrous Calcium. This chemical will then fall apart. That means Gypsum can only hold up to fire once.
Things to keep in mind when using Gypsum drywall
Sometimes, fiberglass reinforcement is added to hold it together better.
However, in reality, a vast majority of gun safes are not added with any structural support for the material they use for fireproofing. So that ends up with what’s left of the Gypsum drywall (Anhydrous Calcium = CaSO4) crumbled into the gun safe’s bottom.
Once the Gypsum drywall is destroyed, there won’t be any insulation between the outside and the inside of the gun safe. Thus, all the items inside the gun safe will have to endure the extremely hot temperatures without any protection left at all.
Another thing to keep in mind is that the real steam is not some harmless steam suspended in the air in your shower. It’s just fog which consists of small droplets of liquid water. The real steam we’re talking about is colorless, very hot (at least 212o), and dangerous.
Once it hits your skin, it will cause near-instant severe burns. In comparison with water at 212o, steam at the same temperature causes more severe burns due to the Latent Heat of Vaporization which causes the steam to have more energy.
Depending on what you store inside your gun safe, steam can be good or bad. Gun safes that are labeled with UL 72 class 125 and UL 72 class 150 can limit the internal relative humidity to keep your contents safe.
This is because you might want to store more things inside your gun safe than just your firearms and ammo, such as documents, electronic media (computer disks…), and photos… Some can be sensitive to humidity caused by the steam.
Thus, even though your gun safe can outlast the fire, make sure you’ll be there as soon as you can to rescue your contents from damages by the steam.
For example, save your media equipment from being ruined by the steam or save the metal parts of your firearms from rusting.
Risks to firearms caused by Gypsum drywall
Recently, people have found a lot of nasty chemicals in Gypsum drywall. When producing Gypsum slurry, the producer adds Formaldehyde as a plasticizer.
However, more often than not, when they finish the manufacturing, this chemical remains at high levels in the Gypsum drywall. Note that this chemical is corrosive to zinc, nickel, copper, and steel.
In some Chinese manufactured Gypsum drywall, FeS2 which is pyrite has high levels.
What’s bad about this chemical is that in humid environments (when the Gypsum drywall heated above 212o releasing steam), the drywall can give off sulfurous gasses which are egg smelling like hydrogen sulfide, carbonyl sulfide, and carbon disulfide.
These gasses react with silver, copper, and other types of corrode metals. A lot of Chinese Gypsum drywall contains the Acidithiobacillus ferroxidase bacteria. This type of bacteria lives in pyrite deposits. They consume sulphur and iron producing sulfuric acid.
There hasn’t been a survey showing that the percentage of Chinese manufactured Gypsum has problems with high pyrite. And it’s confusing for gun safe buys. Some gun safes are made in China.
But they’re labeled as Made in China, and that confuses us even more. Some gun safes are made in the USA. However, they are made with Chinese-manufactured Gypsum.
It’s really hard to know which gun safes are good and which are not. However, cheap gun safes contain higher risks as the gun safe construction will be poorly made.
Gypsum drywall fire protection limitations
Depending on the gun safe manufacturers use Gypsum drywall, it can be a decent fireproofing. True fire rated gun safes apply many of the same chemistry principals. You can mix the Gypsum drywall with concrete to offer fire protection.
However, the percentage of true gun safes is relatively small.
Add structural support for the fireproofing
This is the first issue when it comes to fireproofing and gun safe construction. For example, mix fireproofing material, Gypsum drywall in this case, with concrete.
When the gypsum drywall is destroyed, the concrete will stand up better to fire.
If there is no concrete, the Gypsum will just crumble into the gun safe’s bottom with no structure providing no support for the gun safe at all.
A fully welded steel inner shell is the best option to protect all the items inside the gun safe from the steam and as well as support the fireproofing. Even when the fireproofing material crumbles, the steel inner shell will still hold it in place.
The problem is gun safe manufacturers tend to cut down on steel as it’s the most expensive material in gun safes. That will end up with non-continuous welds and thinner steel.
You can be kind of guess if there is going to be enough steel in the inner shell by judging how much steel and welds the gun safe manufacturer is willing to put on the outer shell.
Reinforced Gypsum fireproofing with fiberglass mesh
This is another option, a less effective one, to add fireproofing to the gun safe construction. Just like the steel inner shell, the fiberglass can hold the Gypsum drywall in place when it crumbles.
Since steel is expensive, some gun safe manufacturers choose to add fiberglass mesh. Because Gypsum drywall will crumble leading to no support to the gun safe at all, gun safe manufacturers will have to add other structures including gussets and support beams to support the gun safe’s total weight.
Structures like that will transmit heat from the outside to the inside of the gun safe directly.
Gypsum drywall falls apart due to age
This is another problem with this type of fireproofing material. Not only it will fall apart after a fire, but it will also fall apart due to age. Sometimes, Gypsum drywall also interferes with the gun safe construction such as the bolt work causing you to perform some fixing.
Above is some knowledge about gun safe construction and everything about the Gypsum drywall fireproofing material. Hopefully, this article can help you make up your mind when purchasing a fire rated gun safe using Gypsum drywall as the fireproofing material.