The 411APKL36 is a full mortise automatic door bottom that installs flush into the bottom of commercial doors to seal air gaps when the door closes. This drop-down seal system prevents air infiltration around door perimeters in office buildings, hotels, dormitories, and upscale residential projects. Pemko designed this unit to mount completely within the door thickness so it does not affect the door's appearance or interfere with floor finishes.
The aluminum housing mortises into doors from 1-3/8" to 1-3/4" thick. When the door closes, the PemkoPrene seal automatically drops down to contact the floor and create an airtight barrier. The seal retracts when the door opens. This automatic operation eliminates manual adjustment and ensures consistent sealing performance. Different end plate kits accommodate various door thicknesses.
| Material | Anodized Aluminum Housing, PemkoPrene Seal |
|---|---|
| Mounting | Full Mortise |
| Length | 36 inches |
| Door Compatibility | 1-3/8" to 1-3/4" thick doors |
| Finish | Mill Aluminum |
| Warranty | 5 Years Limited |
This door bottom meets UL 10C positive pressure fire testing standards for fire door assemblies and UL 1784 air leakage requirements. It also complies with ANSI/BHMA A156.22 door gasketing standards and ASTM E283 air infiltration testing. The unit carries GREENGUARD Gold certification for low chemical emissions.
Installation hardware and end plates are included with each unit. For projects requiring consistent egress performance, review NFPA 101 requirements for door operation forces and accessibility.