How to Replace Vertical Sliding Window Seals

Removal

• The first step in replacing weatherstripping is removing the windows from the wall. Check the top and bottom of the sash on the bottom window and remove any hardware preventing it from leaving the channels on each side of the window. Lift the window up and pull it toward you, twisting slightly if necessary. If your upper window is also designed to slide, pull it down and repeat this process. Depending on the design of your window, you may have to push it out to remove it from the track.

Cleaning

• Pull the old weatherstripping from the sides, top and bottom of your windows. Use a paint scraper to remove any weatherstripping that you cannot remove by hand. After the old weatherstripping is completely removed from the sides of the window, clean each surface to remove any dirt or left-over adhesive. Make sure that each surface is clean and flat. Check the areas of the window frame around the bottom and sides where it comes in contact with the weatherstripping and clean them.

Replacement

• Apply your new weatherstripping to the sides and bottom of the lower window. Use a weather seal on the underside of the window that can withstand compression but will not prevent it from resting flush with the bottom of the window frame. Apply weatherstripping to the outermost vertical sections of the window channels on both sides of the window. Repeat this process for the sides and top of the upper window. Apply a thin layer of weatherstripping on top of the bottom window where it overlaps the window above it to ensure a complete seal.

Considerations

• Mechanical damage will quickly reduce the efficiency of your weatherstripping. Make sure there are no bumpy spots beneath the weatherstripping that will tear it when you move the window. If you have a wooden window sash you can grind these spots down using sandpaper. Self-adhesive weatherstripping is only effective when it is applied to a clean and level surface. If your new weatherstripping does not stick effectively, you can reinforce it using staples applied at 3-inch intervals down the length of the weatherstripping.