Fire-Rated Doors

FIRE-RATED DOORSFire-rated doors, like exit doors with panic hardware, can be installed at egress points and along evacuation paths — but they are also recommended for mechanical rooms, warehouses, and any space where a fire might originate. Their purpose is to contain the fire as long as possible, preventing it from spreading to the rest of the building while occupants evacuate safely.

To perform that function, fire-rated doors must remain closed. That is why the critical piece of hardware on a fire door is the door closer — in daily use it keeps the door from slamming, but in a fire event it ensures that smoke and flame will not pass through an opening that was left open by accident or during a rapid evacuation.

MMI fire-rated doors can be labeled for up to 3 hours of fire resistance in a flush Type F configuration — that is, without vision lites or louvers. When vision lites or louvers are required, the fire-resistance rating varies with the size and type of the insert. The door core is a foamed polystyrene slab, which acts as a fire retardant during a fire event.

For this reason, fire-rated doors ship without topcoat finish — only with a gray rust-inhibitive shop primer, ready for field-applied finish paint.

Depending on the region, fire-rated doors are also referred to as:

  • fire doors
  • fire-resistant doors
  • fire-protection doors
  • labeled fire doors
  • fire-barrier doors
  • smoke-and-fire doors
  • fire-tested doors