Roofing services · Duncan
Moss Removal and Roof Cleaning in Duncan & Cowichan
Cowichan Roofing treats moss and algae while clearing surface debris in Duncan, Lake Cowichan, and Mill Bay. We charge $300 to $1,200 to clean your asphalt shingles and clear out roof valleys. We wash away the growth at low pressure for you.
Duncan gets roughly 1,350 mm of rain a year, compared to about 705 mm in Victoria. Shaded properties under heavy trees get more debris and more moss. Moss comes back on the north slope. We treat the growth at the root and rinse your shingles clean at low pressure.
What does roof moss removal cost?
Our rates run from $300 to $1,200 for moss treatment and surface cleaning. The overall cost depends on tree coverage and the amount of growth on your shingles. Estimates are free, and you receive an upfront price from us. Once you send a note through our website, we reply within 24 hours. We talk through the numbers with you. You always know the full cost before we start cleaning.
How do you treat moss on asphalt shingles?
We treat moss and algae by spraying a diluted 50:50 chlorine solution on the shingles. Then we rinse it clean at low pressure. This liquid treatment kills the growth at the root without damaging the shingle granules. Once the moss loosens, we use a leaf blower, not a scraper, to clear the loosened moss. We gather the fallen debris before we leave so your yard stays clean.
Do you pressure-wash roofs?
We do not pressure-wash asphalt shingles. We treat moss and algae across your roof surface. We remove moss and tree debris while keeping your shingles protected. Moss comes back on the north slope, so we make sure those shaded areas are clean. Quotes are free, and our prices run from $300 to $1,200 for roof cleaning.
Do you clean out roof valleys?
Pine needles, leaves and moss collect in roof valleys and can push water sideways under shingles. Shaded properties with heavy tree cover see extra debris build up in these valleys. We clean the needles and leaves out of your roof valleys so water does not push under your shingles. We treat moss and algae across the roof surface.
Typical price range
$300 – $1,200
Final pricing depends on roof size, pitch, access and material — confirmed in a written quote.
What's included
Spraying diluted chlorine treatment
We spray a diluted 50:50 chlorine solution on your shingles.
Low-pressure water rinsing
We rinse your shingles clean at low pressure, never with a pressure washer.
Clearing moss with leaf blowers
We use a leaf blower to clear the loosened moss off your roof.
Cleaning valley pine needles and leaves
We clear pine needles and leaves from the valleys of your roof.
Gathering fallen yard debris
We pick up the moss and debris that falls into your yard.
Roofing in nearby communities
Keep exploring
- Compare roof costsFull cost ranges for the Cowichan Valley — asphalt, metal, repairs — and what changes the figure.
- Roof RepairRoof leak and flashing repair in Duncan and the Cowichan Valley — chimneys, skylights, valleys, storm damage and lifted shingles. Most repairs $500–$3,000.
- Roof ReplacementFull asphalt re-roofs in Duncan and the Cowichan Valley — tear-off, deck inspection, new underlayment and code-rated venting. Typically $8,000–$20,000, quoted on site.
- Cowichan Roofing home
Get a written roofing quote
Serving Duncan, North Cowichan, Lake Cowichan and Cowichan Bay across the Cowichan Valley Regional District.