Pemko 434ARL36 36" 3' Full Mortise Automatic Door Bottom with Sponge Neoprene Mill Finish Aluminum Finish

The 434ARL36 automatic door bottom creates a complete seal at the base of doors to stop air infiltration, light transfer, and sound transmission. This full mortise unit installs flush into the door bottom and automatically drops a sponge neoprene seal when the door closes. Pemko designed this system to solve energy efficiency problems in commercial buildings where gaps under doors waste heating and cooling.

The low-force actuating mechanism requires minimal door closing pressure to engage the drop-down seal bar. Mill finish anodized aluminum construction handles heavy commercial use. The unit can be field-trimmed up to 2 inches and works on both wood and metal door installations. Mounting hardware ships with each unit.

Length	36 inches
Material	Anodized Aluminum with Sponge Neoprene
Mounting	Full Mortise
Finish	Mill Aluminum
Warranty	5 Years Limited

This door bottom meets UL 10C fire door assembly testing and UL 1784 air leakage standards. It also complies with ANSI/BHMA A156.22 door gasketing requirements and ASTM E-283 air infiltration testing. UL 10C testing validates performance in fire door assemblies under positive pressure conditions. For broader building performance context, NFPA 101 covers life safety egress requirements that work alongside proper door sealing systems.