Pemko 4131CRL 48 Automatic Door Bottom 48 in

Product Description

The PEMKO 4131CRL 48 is an automatic door bottom designed to seal the gap between the bottom of a door and the threshold or floor surface. When the door closes, the mechanism automatically lowers a sponge neoprene seal that compresses against the floor, blocking drafts, sound, dust, and light. When the door opens, the seal retracts to prevent drag and wear. The housing is extruded aluminum with a satin clear anodized finish and measures 48 inches in length. This hardware is installed by door hardware specialists, commercial glaziers, and general contractors on new construction and retrofit projects.

Automatic door bottoms are commonly specified for commercial and institutional buildings where acoustic control, smoke containment, or energy efficiency is required. Typical applications include office suites, hotel corridors, classroom and conference room doors, and entry doors where threshold sealing is needed without a surface-applied sweep. The sponge neoprene seal compresses against a variety of floor surfaces including hardwood, tile, and low-pile carpet. The 48-inch length fits standard 3-0 nominal door widths and can be cut down for narrower applications.

Key Features

• Automatic drop-and-retract mechanism seals on close and lifts on open to prevent floor drag
• Sponge neoprene seal provides compliant compression against uneven or varied floor surfaces
• Satin aluminum clear anodized finish resists corrosion and matches standard commercial door hardware
• 48-inch length fits standard 3-0 doors and can be field-cut for narrower openings
• Suitable for acoustic, draft, light, and smoke-seal applications in commercial and institutional settings

Compatibility

Designed as an OEM-style automatic door bottom for standard commercial door applications requiring a 48-inch sweep seal with a sponge neoprene gasket and aluminum housing.

Installation Notes

Installation is typically performed by a door hardware technician or commercial carpenter. The door must be removed or held stationary while the unit is mortised or surface-mounted to the door bottom per the manufacturer template. Confirm floor clearance before installation to ensure proper seal compression without binding. Fastener torque and strike plate alignment should follow the door manufacturer guidelines and applicable building code requirements.