FHB Logo Facebook LinkedIn Email Pinterest Twitter Instagram Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
SUBSCRIBE TODAY

Save up to

set_percent% off

the cover price

In-depth articles, up-close photography, and detailed illustrations in every issue.

Subscribe Now!
Subscribe
  • How-To
  • Design
  • Tools & Materials
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
  • Join
  • Log In
Subscribe

Fine Homebuilding Project Guides

Windows & Doors

Guide Home
Chapter
  • Choosing Windows
  • Installing Windows In New Walls
  • Retrofitting Windows
  • Window Repairs
  • Door Basics
  • Interior Doors
  • Exterior Doors
How-To

Stop Drafts with a Drop-Down Door Seal

This hidden mechanism retracts when the door is open and eliminates the need for a bulky threshold.

By Jay B. Lane Issue 198

Synopsis: Keeping a house warm in winter and cool in summer can be a tough job. Losing conditioned air under ill-fitting doors is a problem that can be remedied with contractor Jay B. Lane’s technique for installing a drop-down door seal. This mechanism hidden in the door’s bottom retracts when the door is open and eliminates the need to install a bulky threshold. Lane’s process includes the use of a Pemko automatic door bottom. A series of photos illustrates the installation process. This article includes a companion video showing Lane installing weatherstripping in a door opening.

Magazine extra: Watch carpenter Jay B. Lane use a specialty weatherstripping tool to seal a door.

As a custom-door and window installer, I always include weathersealing as part of the job. This final step not only improves comfort and energy performance, but it also shields the home’s interior from wind-driven water, insects, and street noise.

While the weathersealing around the sides and at the top of a door is straightforward, I find that sealing an exterior door at the threshold can be tricky. In most cases, I use an interlocking threshold with a water pan underneath and a rubber silicone bead kerfed into the bottom of the door. However, this approach still leaves a visible metal threshold.

For a seamless transition between interior and exterior spaces, I use an auto-drop threshold seal. It’s an adjustable device with a neoprene seal that retracts when the door is opened to allow for a hidden weatherseal. When the door closes, the door jamb depresses a pin on the hinge side of the door. This action engages a leaf spring inside the mechanism, allowing the neoprene seal to drop into place. I use a Pemko automatic door bottom (www.pemko.com) because of its reasonable price ($35) and its solid assembly.

A hidden auto-drop seal won’t work for every door configuration. The stiff aluminum bar crimped to the neoprene bumper needs a fairly flat surface to seal against. Large gouges or dips and undulations in the floor or threshold below the door cause a gap in the seal. Also, the bottom of the door must be within 1⁄2 in. of the threshold. If the door needs to pass over a thick rug, the threshold can be built up to allow the bottom of the door to be higher. This seal is not recommended for high-exposure areas, but for a clean, seamless look, nothing works as well.


Dial In The Drop

When the door closes, a spring-loaded pin compresses against the hinge-side door jamb to drop the seal. Depressing the pin releases tension on the spring and allows the seal to drop into place. Turning the pin with a screwdriver adjusts the seal up or down. A screw driven flush to the door jamb contacts the pin and prevents it from creating a depression in the wooden jamb. When the door opens, the seal retracts.

When the door closes, a spring-loaded pin compresses against the hinge-side door jamb to drop the seal.

Depressing the pin releases tension on the spring and allows the seal to drop into place. A screw driven flush to the door jamb contacts the pin and prevents it from creating a depression in the wooden jamb.

A Groove Hides The Mechanism

For the weatherseal to operate correctly, the bottom of the door must be no more than 1⁄2 in. above the top of the threshold. The Pemko mechanism requires a groove 9⁄16 in. wide and 19⁄16 in. deep. After fitting a 1⁄2-in.-dia. bit (www.freud.com) in my router, I attach and adjust a fence to center the groove in the door’s bottom edge.
1. Trim the door bottom. For the weatherseal to operate correctly, the bottom of the door must be no more than 1⁄2 in. above the top of the threshold. After marking this dimension on both the hinge and latch sides of the door bottom, I trim the door using a circular saw and a straightedge guide. 2.  Cut the groove with multiple router passes. The Pemko mechanism requires a groove 9⁄16 in. wide and 19⁄16 in. deep. After fitting a 1⁄2-in.-dia. bit (www.freud.com) in my router, I attach and adjust a fence to center the groove in the door’s bottom edge. Then I rout the groove in multiple passes, increasing the cutting depth 1⁄4 in. to 3⁄8 in. each time. I widen the groove to 9⁄16 in. by adjusting the router fence on the final pass.
I move the scribe line clear of the door’s edge and cut the entire mechanism to length with an abrasive grinding blade (a fine-toothed hacksaw will work as well).

I move the scribe line clear of the door’s edge and cut the entire mechanism to length with an abrasive grinding blade (a fine-toothed hacksaw will work as well).

 

Secure with screws glued in placeI secure the bumper by crimping the aluminum bar at one end.

3.  Cut the seal and housing in one step. After I’ve checked the mechanism’s fit in the groove and scribed it to match the width of the door, I move the scribe line clear of the door’s edge and cut the entire mechanism to length with an abrasive grinding blade (a fine-toothed hacksaw will work as well). Note: The neoprene bumper can move laterally inside the housing, so before you cut, make sure its opposite end is flush with the end of the housing.

4.  Secure with screws glued in place. After sealing the inside of the groove and the door bottom with polyurethane sealant, I position the mechanism, drill pilot holes, and attach it with screws. I squeeze a small amount of wood glue into each hole before securing each fastener. I secure the bumper by crimping the aluminum bar at one end.

For more photos and details, click the View PDF button below:

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.

Sign Up
View PDF
Previous: Replacing a Basement Door Next: Simple Door Sweep

Guide

Windows & Doors

Chapter

Exterior Doors

View Comments

  1. orenmax | Aug 14, 2016 08:30pm | #1

    This PDF does not load for me.

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Windows & Doors

Windows & Doors

Trusted, comprehensive guidance from the pros for choosing, installing, replacing, and repairing windows and doors on any house

View Project Guide

View All Project Guides »

Become a member and get unlimited site access, including the Windows & Doors Project Guide.

Start Free Trial

Choosing Windows
  • Window Types
  • Design and Materials
  • Energy-Efficient Windows
Installing Windows In New Walls
  • Installation, Start to Finish
  • Head Flashing for Windows
  • Video Series: Nail-Fin Window over Zip System Sheathing
  • Video Series: Nail-Fin Window over Exterior Rigid-Foam Insulation
  • Video Series: Nail-Fin Window over Housewrap
  • Video Series: Nail-Fin Window over Peel-and-Stick Housewrap
  • Video Series: Nail-Fin Window over a Fluid-Applied WRB
  • Video Series: Weatherproof Window Installation
Retrofitting Windows
  • Removing the Old, Installing the New
  • Video Series: How to Replace a Window
  • Video Series: Install a Full-Frame Replacement Window in a Brick Wall
  • Video Series: Install an Insert Replacement Window in a Brick Wall
  • Video Series: Retrofit a Flanged Window
Window Repairs
  • Restoring Old Windows
  • Repairs and Upgrades
Door Basics
  • Tools & Jigs for Door Hanging
  • How to Install Doors
  • Hinges
  • Handles, Knobs, and Locksets
  • Fixing Door Problems
Interior Doors
  • Prehung Doors
  • Pocket Doors
  • Other Types of Doors
  • Custom-Built Doors
Exterior Doors
  • Door Choices and Design
  • Installing Entry Doors
  • Building Exterior Doors
  • Installing French Doors
  • Replacing a Door
  • Adding Weatherstripping and Sweeps

Fine Homebuilding

Follow

  • twitter
  • facebook
  • instagram
  • pinterest

Newsletter

Get home building tips, offers, and expert advice in your inbox

Sign Up
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences

Taunton Network

  • Green Building Advisor
  • Fine Woodworking
  • Fine Gardening
  • Threads
  • About
  • Contact
  • Advertise
  • Careers
  • Copyright
  • Terms of Use
  • Site Map
  • Do not sell my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2022 The Taunton Press, Inc. All rights reserved.

X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Account

  • Log In
  • Join

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Shop the Store

  • Books
  • DVDs
  • Taunton Workshops

More

  • FHB Ambassadors
  • Reader Projects
  • Podcast
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Sign Up See all newsletters

Follow

  • twitter
  • facebook
  • instagram
  • pinterest

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to set_percent%

Subscribe

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in