To treat cedar shake roofing for maximum longevity in wet climates like Vancouver, a combination of professional chemical treatments and consistent maintenance is required.

Immediately following installation, oil-based preservatives such as copper naphthenate should be applied. These treatments penetrate deep into the wood fibers to inhibit decay organisms and prevent rot or fungal growth. To maintain the natural grain and boost UV resistance, semi-transparent stains are often used in conjunction with these preservatives.

For ongoing care, property owners should follow these treatment and maintenance steps:

• Apply penetrating sealants: These should be brushed onto the shakes every 3 to 5 years to extend the roof’s lifespan to 30 years or more.
• Use fire-retardant treatments: Pressure-treated shakes or topical fire-retardant impregnations can achieve Class B or C fire-resistance ratings, which are often required by local building codes.
• Regular cleaning: Perform low-pressure washing biannually to remove moss and debris without damaging the wood or stripping natural oils. Avoid using harsh chemicals.
• Annual inspections: Conduct yearly visual checks to identify loose shakes or early signs of wear, especially after heavy winter exposure.