All Automatic Door Bottoms

Automatic Door Bottoms

Automatic door bottoms provide a retractable seal along the bottom of a door. The seal drops into position when the door closes and retracts when the door opens, helping close the gap between the door and floor without creating friction during normal operation.

Our selection of automatic door bottoms includes options for different door constructions, installation requirements, and sealing applications. Choose from mortised, semi-mortised, and surface mounted automatic door bottoms, with products available from leading manufacturers including Barzen, Pemko, Zero, and TMH.

Types of Automatic Door Bottoms

The right automatic door bottom depends on the door construction, available installation space, required drop, and the type of seal needed. Common options include:

• Mortised Automatic Door Bottoms: Installed into a channel routed into the bottom of the door for a concealed installation.
• Semi-Mortised Automatic Door Bottoms: Designed for applications where part of the automatic door bottom is recessed into the door.
• Surface Mounted Automatic Door Bottoms: Installed directly onto the face or bottom of the door without requiring a full mortise.

Automatic door bottoms are also available in different lengths, drop sizes, materials, and seal configurations to accommodate different doors and installation conditions.

What Does an Automatic Door Bottom Do?

An automatic door bottom seals the space underneath a door when the door is closed. Unlike a fixed door sweep, the sealing mechanism retracts as the door opens and drops when the door closes. This design can help reduce the passage of air, sound, dust, light, smoke, and other unwanted gaps beneath the door, depending on the specific product and application.

Automatic Door Bottoms for Soundproofing and Sealing

Automatic door bottoms are commonly used where the gap beneath a door needs to be sealed without adding a permanent sweep that drags across the floor. They can be used for applications involving sound control, weatherstripping, air sealing, dust reduction, and light control.

For sound-related applications, select an automatic door bottom with a seal designed for the required gap and door configuration. The actual level of sound reduction depends on the complete door assembly, frame, threshold, surrounding gaps, and other components used with the door.

How to Choose an Automatic Door Bottom

Before selecting an automatic door bottom, consider the following:

• Door type: Determine whether the door is wood, metal, or another construction.
• Installation method: Choose between mortised, semi-mortised, and surface mounted designs.
• Door width: Select the appropriate length or product configuration for the door.
• Undercut or gap: Measure the space that needs to be sealed to determine the required drop.
• Seal material: Consider the application and the type of seal required.
• Operating conditions: Check the product specifications for the intended door and environment.

Accurate measurements are important because an automatic door bottom needs to extend far enough to close the gap while still allowing the door to operate correctly.

Shop Automatic Door Bottoms by Type

Browse our automatic door bottom selection by installation type and manufacturer to find the product that matches your application. Compare surface mounted automatic door bottoms, semi-mortised automatic door bottoms, and mortised automatic door bottoms.

You can also shop by manufacturer, including Barzen automatic door bottoms, TMH automatic door bottoms, Zero automatic door bottoms, and Pemko automatic door bottoms.

Frequently Asked Questions About Automatic Door Bottoms

What is an automatic door bottom?

An automatic door bottom is a retractable sealing device installed along the bottom of a door. It automatically drops when the door closes and retracts when the door opens, helping seal the gap underneath the door.

What is the difference between an automatic door bottom and a door sweep?

An automatic door bottom retracts when the door opens and drops when the door closes. A conventional door sweep remains in contact with the floor or threshold as the door moves. Automatic door bottoms can therefore be useful where a retractable seal is preferred.

Are automatic door bottoms good for soundproofing?

An automatic door bottom can help reduce sound transmission through the gap beneath a door. However, overall sound control depends on the entire door assembly, including the door, frame, perimeter seals, threshold, and other gaps.

What is a drop down door seal?

A drop down door seal is another common term for an automatic door bottom. It uses a mechanism that lowers the seal when the door closes and raises it when the door opens.

What is the difference between mortised and surface mounted automatic door bottoms?

A mortised automatic door bottom is recessed into the bottom of the door, while a surface mounted model is installed directly onto the door. The appropriate option depends on the door construction, available space, and installation requirements.

How do I choose the correct automatic door bottom?

Consider the door material, door width, available installation space, size of the gap beneath the door, required seal drop, and application. Always check the manufacturer's specifications for the specific product before ordering.