The 411ARL36 full mortise automatic door bottom installs into the bottom rail of commercial doors to seal gaps between the door and floor. This drop-down seal automatically lowers when the door closes, creating an airtight barrier that prevents air infiltration and improves energy efficiency in office buildings, hotels, and institutional facilities. Pemko designed this 36-inch unit for 1-3/4 inch thick doors with a mill finish aluminum housing that mortises completely into the door for a clean appearance.
The sponge neoprene seal compresses against the floor to block air leakage while remaining durable under repeated cycling. The automatic mechanism engages through door contact, requiring no electrical connections or manual operation. For facilities managing energy costs and building envelope performance, this door bottom addresses air leakage points that compromise HVAC efficiency.
| Material | Anodized Aluminum Housing, Sponge Neoprene Seal |
|---|---|
| Length | 36 inches |
| Door Thickness | 1-3/4 inch (K411 end plates required for 1-3/8 inch doors) |
| Mounting | Full Mortise with Hardware Included |
| Warranty | 5 Years Limited |
This automatic door bottom meets UL 1784 air leakage standards and UL 10C fire door testing requirements. The unit also complies with ANSI/BHMA A156.22 gasketing standards and ASTM E-283 air infiltration specifications. For projects requiring UL 10C fire door assemblies, this component maintains fire ratings when properly installed. Buildings following NFPA 101 Life Safety Code egress requirements benefit from improved compartmentalization while maintaining code-compliant door operation.