How to Clean Window Sills and Tracks — Toronto Home Guide

Window sills accumulate dust, dead insects, water stains from condensation, and mould from moisture — particularly on the north and east sides of a home where sun dries things less quickly. The window tracks (the channels a sliding window runs in) are even more neglected and develop a thick layer of dirt and debris that is surprisingly satisfying to clean out.

Window Sills

1. Brush or vacuum loose dust, insect remains, and debris first
2. Wipe with a damp cloth and mild dish soap
3. For painted sills with mould: wipe with a diluted bleach solution (1 tablespoon bleach per 2 cups water) and allow to sit for 5 minutes before wiping dry — ensure ventilation
4. Dry thoroughly — a wet painted sill continues to encourage mould growth
5. For wooden sills: use a wood-safe cleaner; bleach can discolour unpainted wood

Window Tracks (Sliding Windows)

1. Vacuum the track first with a crevice attachment to remove loose debris
2. Sprinkle baking soda liberally into the track
3. Pour or spray white vinegar over the baking soda — the fizzing reaction lifts embedded grime
4. Allow to sit for 5–10 minutes
5. Use an old toothbrush to scrub along the track, working the loosened grime into the solution
6. Absorb the liquid and grime with paper towels or an old cloth — push into the corners
7. Use a cotton swab or folded paper towel for the very corners and the weep holes (small drainage holes at the bottom of the track)
8. Wipe dry with a clean cloth

Exterior Sills and Ledges

• Brush off loose dirt and bird droppings first
• Hose down or wipe with soapy water
• Check exterior caulking around the sill — cracked or missing caulk allows water into the wall; re-caulk if needed
• Ensure the exterior sill has a slight slope away from the house — flat sills pool water and cause rot