Description

Pemko 4301_RL Semi-Mortise Auto Door Bottom-Sponge Neoprene Insert

The Pemko 4301_RL Semi-Mortise Auto Door Bottom is a heavy-duty automatic sealing solution designed to eliminate gaps beneath doors and prevent air, smoke, sound, fire, dust, and moisture infiltration. Engineered for commercial and high-traffic applications, the Pemko 4301_RL Semi-Mortise Auto Door Bottom features a drop-down sponge neoprene seal that automatically lowers when the door closes and retracts when opened, ensuring a tight seal without floor drag.

Built with a durable aluminum housing, the Pemko 4301_RL Semi-Mortise Auto Door Bottom uses a jamb-contacting plunger to activate the internal drop-bar seal. This hinge-side actuation mechanism prevents skidding along the threshold and eliminates door hang-up during closing.

Key Features

• Non-Handed Design – Suitable for both left- and right-handed doors
• Semi-Mortise or Full Surface Application
  (When ordering, specify semi-mortise application to receive shorter screws.)
• Smoother Action Positive Seal Mechanism
  Aluminum housing encloses a movable drop-bar seal activated by a jamb-contacting plunger
• Hinge-Side Actuation Mechanism
  Prevents seal skidding and eliminates door hang-up during closing
• End Plates Included for all mounting applications
• Sponge Neoprene Insert
  • Flexible in high and low temperatures
  • Resists deterioration from oily substances
  • Slightly compressible for a tight, reliable seal

Benefits

• Creates an effective barrier against drafts, dust, moisture, insects, fumes, light, and sound
• Prevents seal drag along floors and thresholds
• Ensures smooth door operation without sticking or hanging
• Enhances energy efficiency and indoor comfort
• Ideal for commercial, institutional, and high-traffic environments

Specifications

• Base Material: Aluminum
• Insert Material: Sponge Neoprene
• Fasteners: THSMS #10 x 2″
• Maximum Length: 72″
• Minimum Length: 12″
• Overall Height: 1-25/32″
• Width: 29/32″

Certifications & Compliance

• GREENGUARD Gold Certified
• UL 1784 – Air Leakage Tests of Door Assemblies
• UL 10C – Positive Pressure Fire Tests of Door Assemblies
• ASTM E-283-04 (2012)
• ASTM E90-2009
• ANSI/BHMA A156.22 – Door Gasketing & Edge Seal Systems

The Pemko 4301-RL Automatic Door Bottom is a reliable, high-performance solution for commercial and residential applications where environmental control, fire protection, and sound reduction are essential.

Finish Available

• 4301CRL – Clear Anodized Aluminum
• 4301DRL – Dark Bronze Anodized Aluminum