Sticky fingers, kicks, bangs from backpacks, and nonstop operation test the mettle of every school entry and exit door. Wood doors, while versatile and beautiful, generally won’t survive the use. “A wood door can be gouged and scratched,” says Jeff Wherry, managing director at the Steel Door Institute (SDI) in Westlake, Ohio. “If a steel door is gouged and scratched, it can be bonded.” In fact, steel doors are the only tested door type that has passed the Federal Emergency Management Agency’s tornado tests, says Trent Turner, director of hollow metal marketing at Assa Abloy in Lebanon, Tenn.

Complicating matters is, as always, budget. Even with steel tariffs driving up prices, architects say that the investment in steel doors will pay off.

Portland, Ore.–based BRIC Architecture, which specializes in educational design, opts for galvanized or galvannealed steel exterior doors for schools. Both types of alloys go through the same hot-dip coating process, increasing their durability, and both are zinc-coated and resistant to rust and corrosion. But, galvannealed steel goes through an extra annealing (heat-treatment) process that makes its coating sturdier and more more scratch-resistant. It also has a better paint adherence as its finished surface has a higher absorbency.

The SDI classifies steel doors as standard duty, heavy duty, extra heavy duty, and maximum duty. “We always use [extra heavy duty], 16-gauge door,” says Susan Wurdeman, a specifications writer and associate at BRIC. “Sometimes we’ll even go to maximum duty. … For schools, you need durable [products].”

What’s Inside
Hollow metal doors are available with five standard core types: honeycomb, polystyrene, polyurethane, steel-stiffened, and mineral. A honeycomb core is made of hardened cardboard and can have a fire-rating of up to three hours. A polystyrene core, made of a slab of insulating foam, can also be fire-rated up to three hours. A polyurethane core has better insulating properties, but cannot be fire-rated. Steel-stiffened doors are more durable, can be fire-rated, and reduce sound transmission. Lastly, mineral core doors can reduce heat transfer dramatically, even allowing occupants to pass by doors unaffected by heat from a fire on the other side.

Steel doors can be specified with electronic hardware, as many schools now require keycard access. Doors can be prepped with power supply cables that will plug-and-play with the building power supply, or have conduit preinstalled so that an electrician can install wiring on-site, Turner says.

Looks Matter
Steel doors can be given a faux wood finish with a clear coat that resists stains and graffiti. “[People think] steel doors are industrial and mundane, but if you look at some of the product offerings, you’ll see that there’s a myriad of looks and styles,” Wherry says.

Lites for Daylight
Steel doors can contain half-lites and quarter-lites, or even fashioned into Dutch doors. Steel doors are designed as flush doors, so if a glass lite is added, it requires a panel to be cut out of the door. While fire-resistant lites are available, the cut-out will cause a thermal break, which may be acceptable if the ability to see through the door takes precedence. “In the long run, it’s better to have some way to see who’s out there before you open the door if you can,” Wurdeman says. Fire-, hurricane-, or tornado-rated doors with lites are also available.

Steel doors are tested by the SDI for “strength, quality, consistency, security, weather- and fire-resistance, wear and tear, and longevity” to ensure the highest “manufacturing, performance, and quality standards,” according to the SDI. An SDI–certified door also maintains compliance with ANSI and ASTM standards.