Step 5 · Replace Weatherstripping

Carefully peel or cut away the old weatherstripping from the window sash and frame. Use a putty knife or scraper to remove any adhesive residue. Clean the channels or surfaces where the new weatherstripping will be applied. Select the appropriate type of weatherstripping (e.g., vinyl, foam, or felt) that matches the original or provides a suitable seal. Measure and cut the new weatherstripping to length. Starting at a corner, press the new weatherstripping firmly into place, ensuring it creates a snug fit without being overly compressed, which can hinder window operation. For adhesive-backed types, peel the backing as you go. For compression seals, ensure even pressure is applied.