11 Things to Know About Steel Doors

C.E. Larusso
Written by C.E. Larusso
Updated September 30, 2021
A porch with a white front door
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Everything to know if you're considering a steel door

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To many, a steel door might sound like a strange choice for a family without high-security needs, but it’s actually one of the most popular materials for home entryways. Whether you’re shopping around for a new front door because that old one is looking worse for wear or because the previous owner’s choice just doesn’t match your style, you should definitely compare steel doors against fiberglass or wood and understand the facts before making your decision. For those new to the material, this guide addresses the major considerations.

Steel accounts for nearly half the market of new door installations. The material offers three primary benefits:

  • Security: Many people opt for steel as a security door. A layer of steel “skin” on your doorway will make it extraordinarily difficult to break or damage by hand, foot, or tool and thus less vulnerable to intruders than wood.

  • Durability: For the same reason that steel stands up to deliberate attack, it resists normal wear and tear better than wood or fiberglass competitors. A properly installed and maintained steel door can last for more than 30 years.

  • Energy Efficiency: While steel is a heat conductor, the foam core at the center of steel entry doors offers a high level of insulation. Additionally, a steel door frame typically fits tighter than the other options, meaning less air gets in and out. These features make steel an appealing choice for maintaining the temperature of your home and cutting down on energy bills.

2. They Are Not Solid Steel

Solid steel, often used in military and marine settings, isn’t the type you might install in your home; those usually feature a lightweight core made of foam (either polystyrene or polyurethane) or wood coated in a durable steel skin. A wood frame, called a stile, surrounds it. Solid steel is far too heavy for most residential applications, likely ripping the hinges right out of the frame—and that’s to say nothing of the costs such a volume of the material would impart.

3. Steel Doors Come in a Range of Different Styles

Detail shot of a yellow front door
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Whether you opt for steel because your home needs additional security or because it’s the most affordable option, you’re not limited to the plain, windowless look that might be familiar from your office building’s fire doors. You can pair them with any number of different colors, embossed with an elegant finish, or coated in vinyl that can perfectly mimic wood grain from afar and work well with staining.

4. Steel Isn’t Equally Thick on Every Door

How well a door performs against a security threat or fire is primarily determined by the thickness of the steel skin. Historically, steel’s thickness was measured in gauges on a scale running from four to 28, with the lowest number indicating the thickest material. Though those in the industry and standards bodies now largely follow other measurement practices, it is still commonly used in reference to steel doors. For most home entry doors, the standard option is 24-gauge, which is 0.020 inches thick and weighs about 1.15 pounds per square foot. Some manufacturers also sell 20-gauge varieties with a thickness of .032 inches.

5. Check the Fire Rating

The fire resistance steel doors provide is often a major selling point for homeowners, but not every steel door performs the job equally. Fire-resistant doors have different ratings, reflecting thorough laboratory testing of how long a particular door can withstand flames. At the lowest end, a fire rating of 20 means that the door can hold back the blaze for 20 minutes—with the highest rating indicating up to three hours of protection. As you consider a steel door for your home, make sure to check local building codes; may specify a minimum required fire rating for particular types of entryways.

6. Pay Attention to the Coating

When you purchase a steel door, it may come with factory-applied paint, a layer of primer that allows you to paint it yourself with a brush or spray gun, or an additional PVC coating with its own design, typically wood grain. Industrial-grade factory paint will be the most durable non-PVC option, though you can replace it. A door with a PVC coating will be hardest to customize, so if you choose one, make sure it’s a design you’ll be happy with for years to come. If you’re painting it yourself, just make sure to follow the manufacturer’s instructions.

7. Make Cutouts Before Installation

Steel doors can accommodate the window design or the pet door you need for your home, but you’re better off if a professional makes the cutouts before installing the door. It’s very difficult to cut through the steel yourself, so consult a local door installer about making the adjustments you need.

8. You May Not Be Able to Use an Aluminum Storm Door

If you’re counting on finishing your entryway with the classic look of an aluminum storm door, steel may not be the best option for the main door. Depending on the coating and the composition of the materials, a steel door can absorb high heat levels in direct sunlight. 

Aluminum storm doors can do the same, so, when installed together, it creates the opportunity for lots of heat to build up between them. This not only makes things uncomfortable, but potentially causes the paint on your steel door to peel. For this reason, pairing these types of doors voids many manufacturers’ warranties.

9. Steel Doors Are Inexpensive

Though a steel door might initially sound like a pricey addition to the home, steel doors are quite affordable—in fact, less costly than most fiberglass or wood options. On average, a basic steel door costs between $150 and $300, while you can expect to pay between $200 and $500 for a fire-rated steel door, or somewhere in the range of $200 to $2,500 for a more decorative model. If you want to include sidelights or more elaborate glasswork, expect something towards the top of that range.

10. Steel Is Eco-Friendly

If you’re going for a greener home, steel is an excellent door material choice. Its durability means there’s no limit to the number of times it can be recycled, while most other materials tend to degrade in the process—one reason it stands as the country’s most recycled material.

11. There Are Differences Between Galvanized, Galvannealed, and Cold Rolled Steel

Doors are available with three different types of steel coating:

  • Galvanized steel: Galvanization involves coating carbon steel with a layer of full zinc alloy. This process offers better rust protection but makes the door harder to paint. 

  • Galvannealed steel: Galvannealed steel contains an iron-zinc alloy, which is applied in a hot-dip process during manufacturing, creating a matte texture, making painting a breeze, and which resists moisture damage. 

  • Cold rolled steel: Cold rolled steel follows a mill process that makes it stronger and less likely to warp, and then primed. Cold rolled steel is suitable for interior doors but should be avoided for entry doors since it is more likely to rot. 

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