How to Weatherstrip a Door

That drafty door isn’t going to fix itself. While warped doors or minor foundation settling can cause misalignment, the most common cause of a drafty door is worn or missing weatherstripping. Luckily, weatherstripping a door is a simple process that won’t break the bank and can immediately improve comfort, energy efficiency and pest control.

Below, we’ve explained how to weatherstrip a door, plus the tools you’ll need and when to consider more in-depth repairs. Additionally, we've offered guidance on replacing a door sweep, including common types and how to install them.

What Is Weatherstripping?

Weatherstripping is the strip of material that runs along your door frame and seals tightly against your door when it closes. When installed properly, the weatherstrip’s seal prevents water, air, pests and more from entering your home.

How to Choose the Right Weatherstripping Material

While there are various types of weatherstripping, each with its own claims about longevity and an ultra-tight seal, these are among the most popular options.

• Adhesive-backed. Adhesive weatherstripping, often called foam tape, is a great option for beginners, as it is a peel-and-stick product that's easy to cut and install.
• Metal-reinforced. Metal weatherstripping is a little more involved and requires more tools to install, but it is long-lasting and easily adjustable even after installation.
• Kerf-style. Look along your door jamb for a pre-cut groove called a kerf. This is intended to hold a specialized seal called kerf-style weatherstripping. If your door has a kerf, simply pull out the old weatherstripping (if present) and slide the new kerf-style weatherstripping into the groove.

How to Weatherstrip a Door

Follow these steps to replace your door’s weatherstripping. These steps outline how to install foam tape weatherstripping; adjust accordingly for other types of weatherstripping.

1. Buy your foam tape. Measure your door jamb and buy foam tape with the corresponding width. For most door jambs, this is around 1/2-inch wide. Next, with the door closed, measure the width of the gap and buy foam tape that's thick enough to seal tightly against the door, but not so thick that it prevents the door from operating properly.
2. Remove your existing weatherstripping. Take off the old weatherstripping using whatever tools are necessary. If the existing weatherstripping is adhesive-backed, it will pull off, though it may take some paint along with it. If it is metal, you’ll likely need to remove some screws or pry out some nails.
3. Clean the door and jamb. Once all remnants of the old weatherstripping and door sweep have been removed, thoroughly clean the door and jamb using soapy water, then rinse it and let it dry. Failing to remove all of the old weatherstripping and adequately clean and dry the surface will likely compromise the new weatherstripping.
4. Cut the top strip to length. Measure and cut the foam weatherstripping to length using scissors or a utility knife. For best results, start with the top strip only and measure the full width of the jamb.
5. Install the top strip. Install the top strip by removing the film and pressing it into place on the door jamb.
6. Cut and install the side strips. With the top strip installed, measure each side, then cut and install using the same method.

Tips for Installing Foam Tape Weatherstripping

To ensure your weatherstripping installation goes without a hitch, follow these tips.

• Follow soapy water with isopropyl alcohol. If your door jamb doesn’t feel clean enough, or if the soap left a greasy residue, a 50:50 solution of water and isopropyl alcohol will ensure the surface is as clean as possible.
• Install foam tape when it’s warm. Adhesive doesn’t like the cold. If you’re finding that the foam tape isn’t adhering to the jamb properly, wait for a warmer day or gently warm the jamb using a hair dryer.
• Test the foam tape beforehand. While it’s difficult to perfectly test the foam tape without installation, it’s a good idea to hold it up to the jamb to ensure the door will close properly and the seal is adequate before sticking it in place.

How to Install a Door Sweep

If your weatherstripping is ready for replacement, there’s a good chance your door sweep is, too. The process for replacing a door sweep is very similar to installing new weatherstripping, but the door sweep is mounted to the door itself rather than the door jamb.

How to install a door sweep depends on the type you choose. Here are some popular replacement door sweep options and their installation process:

• Mounted door sweeps. These door sweeps consist of a strip of metal or plastic holding a flexible seal. The strip is cut to length, then screwed to the bottom edge of the door.
• Under-door sweeps. This style of door sweep slides onto the bottom of the door, gripping both sides. Some versions may include holes for securing with screws.
• Adhesive sweeps. Adhesive door sweeps mount in much the same way as foam tape weatherstripping, with an adhesive backing that securely fastens them to the door.