The Importance of Astragals in Commercial Door Hardware

An astragal is a vertical piece of hardware that covers the gap between two doors. Astragals serve many purposes. They can improve door security and enhance energy efficiency. The key is selecting the correct type of astragal. For example, fire-rated astragals can help slow the spread of smoke and flames, while weatherstripped astragals keep drafts and moisture out. Some astragals are designed to reinforce door pairs against tampering or forced entry. Understanding these differences will help you choose the right astragals for your building

Astragals seal the gap where the doors meet. When the doors close, the astragal overlaps or presses against the opposite leaf. This overlap blocks air, smoke, or light from passing through. In fire-rated applications, this seal slows the spread of smoke and flames by tightening the joint between doors. For weatherstripped models, the same action reduces drafts, dust, and moisture infiltration. In turn, this improves the building’s energy efficiency. Astragals also add strength to the meeting edge. Interlocking designs prevent prying tools from being slipped between the doors.

Many codes and standards call for astragals on specific pairs of doors. In fire-rated openings, requirements vary. Older editions of NFPA 80 required overlapping astragals on some rated doors. Newer editions leave it up to the door manufacturer’s listing. For 3-hour fire-rated pairs without a mullion, astragals are often still needed. Even when fire ratings are not involved, model building codes like the IBC may require astragals or similar seals in smoke barriers. Local authorities can also decide if an astragal is necessary based on the door’s use. The safest approach is to check the door manufacturer’s listing and confirm with your local code official. This ensures the opening is both compliant and reliable

1. Overlapping:

• Ideal for preventing both leaves from being active at the same time.

• A coordinator may be necessary for self-closing same-swing pairs.

• Not recommended for push/pull pairs or openings with vertical rod exit devices on both leaves.

• Enhances security when mounted to the outside of the active leaf.

• Comes in two pieces, each attaching to one of the leaves.

• Gasketing meets in the middle, covering the gap seamlessly.

• Allows both leafs to remain active without specific opening or closing sequences.

• Suitable for push/pull pairs and openings with vertical rod exit devices on both leaves.

Selecting the appropriate astragal involves considering factors such as security, door usage, and manufacturer specifications. Overlapping provides heightened security but requires more coordination, while split astragals offer flexibility in leaf activity. The manufacturer's listing often guides the choice, specifying the type of astragal suitable for particular doors (especially for fire-rated doors).

Choose CDF Distributors for expert solutions that meet your security and compliance needs. Our professionals will guide you to the correct astrogals for your doors and answer any questions along the way.