How to seal a window

Selecting the right weather strip is important for creating a good window seal. You need to make sure you achieve a snug fit, so consider the gap size when choosing your weather strip.

There are many types of weather strips to choose from, but rubber window seals or foam strips are the most versatile. They’re suitable for uneven gaps and come in a variety of thicknesses and widths.

Measure the height and width of your window frame to work out how much weather strip seal you will need. Add a little extra as you don’t want to run out – that might result in gaps and air leaks.

Once you’re happy with your measurements, cut the weather strip to size. Use sharp scissors for a clean cut to ensure the strip fits perfectly within the frame. If you’re not sure, leave a little more length on the cut. You can always trim it down to size later using a utility knife.

Before applying the weather strip, clean the window frame. This will ensure the adhesive sticks properly and won’t peel off in a few months’ time. Use a brush and a damp microfibre cloth and clean the frame until it’s spotless.

To apply the weather strip, start in one corner and work your way around the frame, pressing firmly as you go. Don’t pull the strip: that will stretch it out and make it less effective.

Close the window to check for any draughts. A well-sealed window should have no visible gaps and you shouldn’t feel any cool draughts coming through. If there are any, repeat the above steps and apply more of the weather strip.

Learn how to caulk a window frame.