The STC411APK36 automatic door bottom installs into the bottom rail of commercial doors to provide acoustic sealing and air leakage control. This 36-inch mortise-mount unit automatically drops a PemkoPrene seal bar when the door closes, creating an airtight perimeter seal at the threshold. Pemko designed this unit for hotels, office buildings, and other commercial spaces where sound transmission and energy efficiency matter.
The aluminum housing mortises fully into the door bottom, working on both right and left hand doors. The proprietary PemkoPrene seal material compresses against the floor to block air infiltration and reduce sound transmission between rooms. Mill finish aluminum provides corrosion resistance in high-traffic applications.
| Material | Anodized Aluminum, PemkoPrene Seal |
|---|---|
| Length | 36 inches |
| Door Thickness | 1-3/8 inch |
| Mounting | Full Mortise |
| Warranty | 5 Year Limited |
This door bottom meets UL 10C fire door assembly testing and UL 1784 air leakage standards. ANSI/BHMA A156.22 certification confirms performance as a door gasketing system. ASTM E283 testing validates air infiltration resistance.
Fire door assemblies require annual inspection per NFPA 80 standards, covered in our UL 10C fire door testing guide. For broader egress code context on commercial door requirements, see NFPA 101 Life Safety Code reference materials.