Up to 4.5"of 2300° Ceramic Wool & Glass Blanket

Illustration of a gun safe cut out on a white background

2.5" 2300° Ceramic Wool

2.5" applied seamlessly to the entire interior.

3/8" Solid Door Plate

2" Glass Blanket

2" is applied to the top and bottom of the safe, while 1" is applied to the door.

4 Gauge Body

Nearly 1/4" thick.

16 Gauge Steel Liner

Fully encases the entire interior.

We build every fire-lined safe with the exact same insulation used in industrial ovens and kilns which are designed to handle over 2,300°F of relentless heat. These materials don’t just “slow down” heat, they block it.

It holds it's shape and fire resistance strength even after being exposed to extreme temperatures.

  • Each right, left, and back wall, along with the door jambs, is packed with 2½ inches of 2300°F-rated, 8 lb. density ceramic wool, compressed to 2¼ inches
  • The top and bottom walls will have 2.5" of ceramic insulator and 2" of glass blanket, compressed to 4". 
  • The door will have 2.5" of ceramic insulator and 1" glass blanket, compressed to 3".

Sturdy gives you more of this premium ceramic and glass insulation than most manufacturers. Thicker layers, denser coverage, and complete protection from top to bottom. While others cut corners to save costs, we pack in every inch of heat-blocking material your safe can hold without weak spots. Every inch of your safe — walls, door, top, and bottom — is packed with perfectly compressed insulation that won’t shift, sag, or leave gaps over time.

A rugged 16-gauge steel interior liner helps compress and cover the insulation material. It also adds more strength, so your shelves won’t buckle under pressure like others anchoring shelving into drywall and thin felt. You can also do things such as add magnet storage systems inside and decorative vinyl stickers.

Watch the Magic Happen: See How It's Applied.

fire gasket used on gun safes

Sturdy Fire Gasket

The weakest point on most fire safes is the door seal. If heat and smoke slip through that tiny gap, everything inside is at risk. That’s why we use the same sealing technology trusted in industrial ovens and kilns. Places built to handle extreme, nonstop heat. Every Sturdy Gun Safe with fire lining features a UL-tested fire caulking and a precision-fit boiler gasket, not the cheap, one-size-fits-all gaskets most safes use.

Here’s what makes ours different:

  • Real fire defense: Our LCI Firestop Sealant can block fire, smoke, and moisture for up to 3 hours, and when temperatures rise, it expands up to eight times its size to form a complete seal.
  • More coverage = more protection: Our boiler gasket is twice as wide as the average competitor’s, giving you 2× the sealing power where it matters most, around the door.
  • Custom-fit seal: No two safes have exactly the same door clearance, so we custom-fit every gasket for a perfect seal right from the start. Competitors often use Palusol gaskets, which only expand after they get hot.

Watch a video on how they are applied.

man confused about gun safe fire rating

What's Our Fire Rating?

We don’t advertise a “fire rating” like a lot of other safe companies do and that’s on purpose. We refuse to mislead our customers with numbers that don’t actually mean anything in the real world. Our competitors either use made-up fire ratings or incomplete tests that skip key steps, such as including the excessively long cool down time where items are still cooking! Right now, there are no long-gun RSC safes on the market with a true UL fire rating. A UL security rating, which tells you how hard it is to break into a safe, does not mean the safe is fireproof either.
Truth About Ratings
gun safe fire proof test comparisons

How We Tested Vs. Our Competitors

Some safe companies test their fire proof safes in controlled testing furnaces which perform like oversized house ovens yet get a lot hotter than your normal oven. These safe companies eliminate 2 important factors when testing their gun safes to get those ratings: Point Of No Return, and Cool Down Time. Read more about how Sturdy Safe vs. other gun safe companies test for fire ratings.
Real Burns
sturdy gun safe in house fire without fire proofing

Fire Resistance: Optional, Not Mandatory

Fire-resistant safes aren’t for everyone—and with Sturdy Safe, you only pay for what you need. If you’re on a budget, it’s smarter to choose our uninsulated safe with thick steel than a thin, sheetrock-lined safe that offers little real protection. If your insurance covers contents, you’re near a fire department, keep the safe in a low-burn area (like brick or concrete), or have sprinklers, insulation may not be necessary. One of our uninsulated safes even withstood a partial house fire (13-minute response time), proving thick steel and size alone provide some fire resistance—though not as much as our insulated models.
Unlined Safe Survival Story

Real House Fire Results

1st House Fire

A long time ago a man named Stan lost his house to a fire. A volunteer fire department reported to the blaze but there wasn't much left to save. See how our model 3627-6 gun safe survived a house burn with ease. Read More

2nd House Fire

In 2017 there were two Sturdy Safes involved in a 100% complete burn down. A volunteer fire department reported to the blaze but couldn't get any water to the house. No long gun safes currently on the market are designed to survive a burn down like this. Read More

Competitors Insulators

gun safe with sheetrock fire proofing pouring out

Fire Board

Regardless of their fire ratings, they won’t perform as claimed. One must understand how safe manufacturers test safes for fire to understand how testing facilities come up with those inaccurate fire ratings. UL will tell you not to bother testing safes for fire resistance lined with fire board. Read more about Fire Board being a terrible gun safe insulator.
It's Terrible
gun safe with cement fire liner

Cement and "Light Cement"

UL actually gives decent fire and security ratings to safes lined with real cement (like in certain high security TL safes). The problem with real cement liners is the cost of the safe itself as well as their extreme weights. Don't get real cement liners confused with light weight dry "cement" composite fire insulation, which don't add much in the way of security.
So Confusing
gun safe with fire proofing added in weird places

Ceramic Wool

Even though this material is the best fire insulator, the problem lies in the manufacturer not giving you enough of it. Some do as little as lining just the top of the safe due to its high cost and mislead you to believe they line the whole safe with it.
Show Me The Ceramic