Peeling – Wood Substrates & Moisture

Peeling can result when wood expands and contracts from moisture, eventually causing a paint coating to loosen. Moisture reaches painted wood in a number of ways:

  1. Through uncaulked joints
  2. Through worn-out caulk
  3. Gutters full of ice or debris
  4. From moisture inside the building
  5. Through damp basements
  6. Painted boards too close to ground
  7. Plant growth
  8. Leaky roofs

Peeling can also result when painting over wood that has had insufficient drying time after exposure to moisture from rain, dew or pressure-washing.


  • Eliminate the source of moisture:
    1. Remove and replace loose and worn caulk.
    2. Install vents/fans to remove moisture from inside the building.
    3. Waterproof the foundations.
    4. Remove wood touching the ground.
    5. Clean out gutter and downspouts.
    6. Install wedges under siding boards.
  • Allow damp or wet wood to dry for 3 to 5 days before painting.
  • If pressure-washing above 500 psi (not recommended), allow up to 3 weeks’ drying time.
  • Remove all loose paint.
  • Feather any rough edges with sandpaper.
  • Spot-prime all bare areas with exterior primer.

Note: For more information regarding moisture inside homes and possible remedies, obtain a copy of Canada Mortgage and Housing Corporation’s “Moisture and Air – Problems and Remedies” by calling their Victoria office at (250) 363-8040 or by calling your local CMHC office.