How to Fix a Drafty Window Without Replacing It

Seal drafty windows by applying weatherstripping around the frame, caulking gaps, and adding plastic film or storm windows for immediate improvement without costly replacement.

  1. Find the Cold Spots First. Hold a lit candle or incense stick around the window frame while moving slowly along all edges. Watch for flickering flames or moving smoke that indicates air movement. Check the sash where the window meets the frame, corners of the frame, and where the frame meets the wall. Feel with your hand for cold spots or moving air on windy days.
  2. Clear Away the Gunk. Remove dirt, old paint chips, and debris from all surfaces where you'll apply weatherstripping or caulk. Use a putty knife to scrape away loose material and vacuum out crevices. Wipe down with a damp cloth and let dry completely. Clean surfaces ensure better adhesion for sealing materials.
  3. Seal the Moving Edges. Measure and cut self-adhesive foam tape or V-strip weatherstripping to fit the sides and top of the window sash. Press firmly into place on the window frame where the sash closes against it. For double-hung windows, apply strips to both the upper and lower sash channels. Make sure the window still opens and closes smoothly without binding.
  4. Seal the Fixed Gaps. Load a caulk gun with paintable acrylic latex caulk and cut the tip at a 45-degree angle. Apply a steady bead of caulk along the joint where the window frame meets the wall, both inside and outside if accessible. Smooth with your finger dipped in water for a clean finish. Remove excess immediately with a damp cloth.
  5. Add an Insulation Layer. Clean the glass thoroughly and apply double-sided tape around the window frame according to the film kit instructions. Unroll the plastic film and press it onto the tape, leaving some slack. Use a hair dryer on low heat to shrink the film tight and remove wrinkles. Trim excess film with a utility knife.
  6. Block Floor-Level Air. For windows that sit close to the floor or have gaps underneath, place a fabric draft stopper filled with rice or sand along the bottom edge. You can make one by filling a long sock or tube of fabric, or purchase a commercial door snake. This blocks air movement at floor level.