Learn safe, effective methods for removing moss and lichen from wood shake and shingle roofs. Protect your roof's life, prevent water damage, and avoid costly repairs.

How to Clean Moss and Lichen Off a Wood Roof Without Damaging It

Wood Roofing
October 21, 2025•3 min read

Wood roofing is popular for its natural beauty and long lifespan—but only if properly maintained. In Colorado’s damp, shaded areas (like Greeley, Boulder, or Evergreen), moss and lichen can quickly take hold on wood shake and shingle roofs. Left untreated, they trap moisture, accelerate decay, and void warranties.

Here’s how to clean your wood roof without causing more harm than good.

Why Moss and Lichen Are a Problem on Wood Roofs

  • Retain moisture: This speeds up wood rot and shortens roof life.

  • Lift shingles: Growth under or between shakes can dislodge pieces.

  • Attract insects: Damp, rotting wood is a magnet for termites and carpenter ants.

  • Void warranties: Most manufacturers won’t cover roofs with biological growth.

Best Time to Clean a Wood Roof

Late spring or early fall works best:

  • Weather is mild.

  • Roof is dry enough to clean but not sunbaked.

  • Growth is most visible and manageable.

How to Clean Lichen and Moss Off a Wood Roof

1. Inspect First

Before any cleaning, walk the perimeter and use binoculars to look for:

  • Soft or spongy wood

  • Curled or cupped shakes

  • Excessive buildup in valleys or under flashings

Avoid walking on the roof if possible—it’s easy to crack shakes.

2. Manual Removal (Gentle Is Key)

For light moss:

  • Use a soft-bristle brush or plastic putty knife

  • Brush downward with the grain of the wood

Do NOT use:

  • Pressure washers

  • Wire brushes

  • Scraping tools

These methods strip wood fibers and open the surface to water intrusion.

3. Apply a Roof-Safe Cleaning Solution

Choose one of the following:

  • 50/50 white vinegar and water

  • Oxygen bleach (sodium percarbonate), mixed per label

  • Commercial wood roof cleaners approved by the Cedar Shake & Shingle Bureau (CSSB)

Spray using a garden sprayer, let sit 15–30 minutes, and rinse gently with a low-pressure garden hose.

Never use:

  • Chlorine bleach (damages wood fibers)

  • Acid-based cleaners

  • Any cleaner not approved for wood roofing

4. Rinse and Assess

Use a standard garden hose with a fan spray nozzle. Rinse gently from the ridge down. Don’t force water under shingles.

Prevent Moss and Lichen from Coming Back

  • Trim nearby trees to let sunlight dry the roof

  • Clean your gutters regularly to prevent roof runoff from pooling

  • Install copper or zinc strips near the ridge to discourage growth

  • Schedule regular maintenance every 3–5 years with a certified cedar roof specialist

FAQs

How often should I clean my wood roof?
Every 3 to 5 years, or as soon as moss or lichen appears.

Can I pressure wash my wood roof?
No. According to the Cedar Shake & Shingle Bureau, pressure washing damages wood fibers and shortens the roof’s life.

What’s the safest moss killer for wood roofs?
Oxygen bleach (sodium percarbonate) is gentle and effective when used properly.

Serving Colorado & Georgia Homeowners

At Roof Nuts, we specialize in cedar shake and wood shingle roofing care in:

  • Colorado: Denver, Boulder, Fort Collins, Colorado Springs, Greeley, and surrounding areas

  • Georgia: Atlanta, Augusta, Athens, and beyond

Let us help you maintain the beauty and life of your wood roof.

📞 Call today:
Colorado: 303-276-2403
Georgia: 404-476-6851
🌐 Visit us at RoofNutsCO.com or RoofNutsGA.com

Custom HTML/CSS/JAVASCRIPT
Back to Blog