What is Fireproof Insulation?

Ken Black

Fireproof insulation is insulation made of a fire retardant material. It may be used in building materials, clothing or other applications fireproofing is needed. This type of insulation may be made from special materials not normally used for other applications, or may be standard insulating materials coated with a fireproof layer.


Fireproof insulation is usually made of one of four basic types of materials. Each material has its benefits, its appropriate uses and its limitations. These materials include fiberglass, glass wool, polymers and natural products, which may or may not be treated with other substances.

It is important, when looking at materials, to understand that fireproof insulation types may only be most effective at certain temperatures. Once those temperatures are exceeded, the entire material could be broken down and the insulation would become ineffective. Fiberglass should only be used to temperatures up to 212 degrees Fahrenheit (100° Celsius). Glass wool may be used between 212° Fahrenheit (100° Celsius) and 1,220° F (660° C). Many types of polymers are rated for temperatures up to 2,220° F (1,215° C). Some natural fireproof insulation can withstand temperatures as high as 3,000° F (1,649° C).

One of the most common uses for fireproof insulation is in attics and walls of various types of buildings, including homes and commercial establishments. Most of the standard insulation included will be able to resist some fires. It should be noted that most insulation is not truly fireproof, but rather fire resistant. There may be times when the material, through an abundance of fire or heat, will succumb to fire.

Another use of this type of insulation is in clothing used by those who will be working closely with fire. This will include occupations such as firefighting and some industrial jobs, where coming into close proximity to fire could be a normal part of the daily routine. In these cases, the insulation's first job is to protect against heat, but in cases where the clothing comes into direct contact with a flame, the fireproof insulation has a secondary purpose which is no less important.

When considering fireproof insulation, it is important to consider what the insulation will need to resist and endure on a daily basis. Once that is determined, it is then possible to choose materials and types. For a building, fireproof insulation can come in the form of foam boards, rolls or loose foam insulation that is often sprayed into an area such as an attic or wall.

You might also Like

Readers Also Love

Discussion Comments


Very good post. People should be made more aware of the importance of good fireproofing by the fire brigade, and I don't mean popping around the neighborhood once in a blue moon checking if everyone's still got a battery in their fire alarm.

Just a few simple steps, like using flame retardant insulation, intumescent sprays and other passive fire protection methods on the more fire-prone areas of your house can be the difference between a small, easily contained fire, and your house and possessions literally going up in smoke.


@Malka - Hi there. Even though it's more expensive, for the absolute maximum safety, you should replace both pieces of insulation entirely.

Before you freak about the price and having to pay it, though, think about how important it is for this to be the highest safety available. Patching it is almost as effective as replacing the sections entirely, and probably more than adequate enough to fire proof your kitchen walls until you or firemen could get there and put the fire out.

The fact that there is an upright strut in between the pieces of fireproof insulation is a good lesson, too. There's a gap between those two pieces of insulation to fit the board into.

If you patched up the hole in the fire proof insulation with pieces cut to fit the spots where the insulation was torn through, the gaps between the pieces of insulation in each section would be much smaller than that gap for the strut to fit into.

My advice is to patch the holes up using pieces of fire proof insulation cut to be a bit too big. Insulation squishes -- squish the pieces into the holes, and they will fill up any gaps that way, leaving a perfectly effective fire proof layer of insulation inside your kitchen wall.

The only difference in effectiveness will be the paper backing on the insulation -- and that's not the functional part, anyway, it's just there to make stapling the insulation to the upright struts easier. Good luck!


Does anybody have any advice for what to do if you have blown the insulation through in one spot on a wall? In the case of fire proof insulation, do you think it would be less effective in blocking flames if I patched it up instead of replacing the whole section of insulation there?

The spot that got blown through was basically rammed through by accident when somebody broke the wall in the other room. It's right on the seam between two pieces of insulation -- the only reason the wall didn't crack much worse is that there was an upright strut right in the middle, too.

Anyway, replacing the insulation would cost more than I really want to pay for the repairs, especially since if I can't patch it, I'll have to replace both sections of insulation instead of just one. Fire proof insulation costs more than the regular kind, but as SkittisH said, it's important to plan ahead just in case. This is my kitchen, so I think it's important to make it fire proof.

Any advice on how effective a plain old patch would be instead? I don't want to do it if it will be dangerous that way, but even a patch is safer than it is now -- a hole in the wall.


@seHiro - Wow, when I looked up "fire proof insulation" it didn't even occur to me that people would want to insulate themselves instead of the walls of a house. That's pretty interesting stuff.

So, what exactly is Zel Gel made out of? The articles mentions regular fire proof insulation being made of materials like fiberglass, polymers and wool, but that sounds more like something for rigid insulation you would find inside a house only.

I can't see those kinds of substances still being fire proof and safe for contact with the skin after being turned into a white powder and mixed up into goop. Zel Gel must be made out of something that doesn't bother the skin, and that isn't toxic, or it wouldn't be considered safe to smear all over somebody.

Speaking of smearing gel all over somebody, you noted that Zel Gel could be put in the hair, but considering the fact that it solidifies when it lights up, I'll bet the face is still off-limits for fire scenes. The eyes would just be in too much danger in a situation like that; that, and stunt actors need to be able to see to play their roles.

So what's it made out of? I'm all curious about this stuff now -- I'm going to have to track down a making of Water World documentary, if there is one.


One of the biggest breakthroughs in fire proof insulation for humans in situations such as stunt actors being lit on fire is the material known as Zel Gel.

Zel Gel, named after creator Gary Zeller, has been around since the late 1980s. In fact, Gary Zeller got an Oscar in 1989 for inventing it, because it was just that useful. The movie "Water World" used heaps of explosions and flames in its special effects, including lighting people on fire, and they used Zel Gel to make the process safer.

So what is Zel Gel? It is literally a gelatinous translucent goop that you mix up in a bucket from a white powder. You can smear it directly onto your skin, clothes and even hair, and it creates the best insulation against being lit on fire that stunt actors have yet had access to.

Zel Gel can burn for two minutes straight before it becomes dangerous to the person coated in it. To put things in perspective a bit, in the 1970s before Zel Gel was created, stunt people wore full body suits that resisted flames for all of fifteen seconds!

When Zel Gel gets lit on fire, it not only feeds the flames as a form of fuel, but it also becomes more gelatinous, solidifying enough that you can't fling it off like you could in the original goop stage when you smeared it on. It stops burning when you pour water on it -- truly a useful substance for movie makers worldwide.


If there's anywhere in your house that should have fire proof insulation the most, make it the room that holds the water heater.

It might sound silly, since the water heater is full of water, but pipe insulation goes on the outside of the pipes -- in the event that there is a problem with too much heat and the pipes don't burst, there is the very real possibility that your water heater room or closet could burst into flames.

I mention the water heater because for many homes, it's the most consistently heated place in the house. Even the regular heating heaters don't stay on as much as the water heater, because people like hot showers and baths year-round, even when the heaters have been switched to air conditioning for the summer.

After the water heater room, the most important place to insulate with fire proof insulation is probably anywhere near the heaters -- which are on the second most frequently -- and then the stove in the kitchen.

Kitchen stoves are on very often but only in short bursts. On the off chance that somebody leaves the oven on for hours or starts a grease fire or anything, though, it's reassuring to know the walls wouldn't burn all the way through to any other rooms.

This is all the worst case scenario, mind you. When you make things fire proof, you're planning ahead just in case.

Post your comments
Forgot password?