How to Install Weather Stripping on a Door

Weather stripping is a seal or gasket fitted around the edge of a door to fill gaps and keep out water, air and dust. You can do the job yourself in about an hour, using a tape measure, a few hand tools and a strip chosen to suit your door. This guide covers how to check whether you need it, how to fit it, and how to replace an old seal.

• Tape measure and pencil
• Cleaning cloth and soapy water
• Sandpaper
• Screwdriver
• Scissors
• Nails or heavy-duty staples
• Hammer
• A weatherstrip suited to your door, such as V seal, sponge tape or a brush seal

1. Inspect the door hinges and tighten any that are loose, as loose hinges can cause draughts. Loose doorknobs can also affect your indoor temperature if left unaddressed. If the screws will not tighten all the way, use wood plugs before reinforcing tighter screws.
2. Measure the gap between the door and the door jamb with your tape measure to work out the thickness of weather stripping you need. Note the width and height of the top of the frame with the door closed, so you know how much stripping to buy. Add a buffer of at least 10% to your measurements for safety.
3. Choose the type of weather stripping that suits your door. V seals are made from expanded rubber and fold into a V shape when compressed to create a watertight seal. Sponge tape has a self-adhesive backing, is made from closed-cell sponge rubber and comes in a range of thicknesses, making it ideal for irregularly shaped gaps around the tops and bottoms of door frames. Brush seals are made from polyurethane, are inexpensive and easy to install, but are less durable than other types and best used in low-traffic areas.
4. Clean the door and jamb before fitting anything. Weather strips are best applied to clean, dry surfaces, so wipe the door with soapy water and a clean rag, and scrub sandpaper over any areas with residue to get a seamless surface.
5. Mark the weather stripping with a pencil according to your measurements and cut it to fit the top and sides. Check that the first cuts fit the areas properly before going further, and remember it is better to trim off excess than to cut too short.
6. Fix the weather stripping in place. Depending on the type you have chosen, stick, tack or otherwise affix it carefully, applying enough pressure where needed. If you are working with adhesives, you can strengthen the installation with staples or nails.
7. Fasten a door sweep at the base of the door. Pre-drilling the holes makes it easier to apply with a screwdriver later on.

Door draughts can cause heat loss in a home by as much as 25%, so sealing them is an energy-efficient way to minimise hot or freezing air leaks, unwanted rain or snow, and even to act as a barrier to bugs or pests.

Checking your weather stripping is a good year-round practice, but that does not mean you need to replace it every year. Monitoring its condition makes it easier to get ahead of problems before leaks happen. Double-check your door weather stripping every few years, and pick a time when the weather is dry enough to allow for easier application.

To remove old weather stripping, the method depends on the type you have. Adhesives are the easiest to take off, as they can be peeled from the door frame. If your stripping has been fastened with screws and nail tacks, remove them with a screwdriver and pliers. Clean the door frame as you go, so unwanted residue does not stick to the door jambs.

If your door frame is warped, rotting or bent, this can create gaps that let air pass through. Replacing the weatherseal can help seal the gap, but extensive damage may require more significant repairs or replacement. Replacing window seals and weatherstrips is considered a DIY job, but it is sometimes necessary to consult a glazing professional.

How do I know if I need weather stripping? Start with a visual inspection for gaps or cracks in the existing seal, as weatherstrips can degrade, become over-compressed, tear or detach over time. You can also aim a flashlight at the outside of the door and look for light shining through the frame.

What is the paper test? Close the door on a piece of paper and try to pull the paper out without tearing it. If it slides out easily, there is a gap that air, moisture or water could pass through, which shows a replacement weatherseal is needed.

Can I just feel for draughts instead? Yes. On a windy day, feel around the edge of your door for draughts and areas where cold air may be getting in. You can use your hand or a thin piece of fabric to detect air movement.

What are the signs of air leaks in colder months? Look for excessive condensation near the edges of doors and windows during the winter. It can be an indicator of air leaks, as cold moist air enters through gaps and condenses into water droplets on cooler surfaces.

Should I get a professional to check? For a thorough assessment, you can pay for a professional energy audit. An energy auditor can carry out tests such as a blower door test to pinpoint air leaks, and use thermal imaging cameras to highlight cold and damp areas around your doors and windows.