Rolling Door Curtain

A rolling door curtain is the continuous array of formed metal slats that makes up the door surface of a rolling steel door. Each slat is roll-formed from steel sheet into a curved profile with a male edge along the top and a female edge along the bottom. Neighboring slats interlock along those edges so the curtain acts as a rigid panel when it hangs closed in the guides, but the curved profile allows each joint to pivot, letting the whole assembly coil into a tight roll around the barrel above the opening.

The curtain is the primary weather and security barrier of a rolling door. It fills the space between two vertical guides on each jamb and is held in those guides along its full height when closed. When the door opens, the bottom bar rises, the slats pivot at each interlocking joint, and the curtain wraps around the barrel. As the curtain coils, the roll grows in diameter, which is why rolling doors require a hood or adequate headroom above the opening.

Slat materials and profiles:

• Galvanized steel - Standard for most commercial applications; resists rust and handles physical impact.
• Stainless steel - Used in food-service or corrosive environments.
• Perforated slats - Punched with holes to allow air movement and visibility. Common in parking structures.
• Flat-face slats - Provide a cleaner visual appearance on interior applications.

Slat width (the depth of each formed strip) typically runs 2 to 4 inches. Narrower slats create a tighter coil diameter and require less headroom. The gauge of the steel determines the curtain's resistance to impact and wind pressure.

The rolling door bottom bar reinforces the lowest edge of the curtain and carries the sensing edge or astragal seal. The curtain edges travel in the vertical guides on each jamb. At the top, the curtain attaches to the barrel, which is part of the counterbalance assembly in the hood above.

A rolling grille door uses a similar coiling mechanism but replaces the solid slats with open mesh links, sacrificing weather protection for visibility and ventilation.