• In this video, This Old House general contractor Tom Silva explains how to insulate a window with sash weights.

    Steps:

    1 Use hammer and pry bar to remove the molding from around the window.
    2 Cut a strip of foil-faced rigid foam insulation to fit snugly into the space between the side jamb and plaster or drywall.
    3 Spray some maximum-expanding polyurethane foam sealant into the space at the bottom and top of the window’s side jamb.
    4 Press the strip of foil-faced insulation into place alongside the side jamb, flush with the wall.
    5 Repeat the above procedure for the opposite side jamb.
    6 Cover the seam between rigid-foam insulation and wall with adhesive-backed foil tape.
    7 Plug the hole where the rope meets pulley with a small strip of rubber carpet padding.
    8 Replace molding around window.
    • Difficulty: Easy to moderate
      The hardest part is removing and replacing the window trim
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    Video Directory

    Selected Topic/Section

      Tools List

      • hammer
        Hammer
        used to remove molding from around window
      • flat prybar
        Pry bar,
        used to remove molding from around window
      • utility knife
        Utility knife,
        for cutting rigid foam insulation

      Shopping List

      1. Foil-faced rigid foam insulation
      used to fill gaps between side jamb and rough opening

      2. Minimal-expanding polyurethane foam sealant
      used to insulate spaces around window

      3. Maximum-expanding polyurethane foam sealant
      used to insulate spaces around window

      4. Foil tape
      for sealing joint between rigid foam insulation and wall surface

      5. Foam rubber carpet pad
      used to plug hole at each pulley

      6. Finishing nails
      for replacing the window molding