Duncan Cedar Shake Roof Treatment

No. Pressure washing cedar shakes splits wood fibres, permanently damaging the shingles and voiding manufacturer warranties. It also doesn't kill the organisms — within 60–90 days, moss and lichen regrow as thick as before. Professional low-pressure biocide treatment is the correct method.

In Vancouver Island's climate, cedar shake roofs benefit from professional treatment every 2–3 years. Properties with heavy tree canopy or north-facing roof sections may require treatment every 18–24 months. Roof Labs Canada provides free assessments for all cedar properties.

Cedar shake treatment costs $0.40–$1.20 per square foot on Vancouver Island, slightly higher than asphalt treatment due to the specialist formulations and additional care required. Most standard homes cost $700–$1,200 depending on roof complexity and coverage.

Yes. Roof Labs Canada's cedar formulations include a penetrating wood preservative component that conditions the cedar fibre while eliminating biological growth. This extends cedar shake life beyond what biocide alone achieves.

Our cedar-specific formulations meet standards for use on properties with rainwater collection systems — important on Gulf Islands and rural Vancouver Island properties. We follow Health Canada guidelines for all products used on cedar.