How to Prevent Moss From Growing On the Roof

Moss and algae can do considerable damage if they’re left for too long. Both use the combination of moisture and organic materials – aka your roofing materials – to grow and colonize. As a result, structural materials begin to rot and decay, leading to expensive, long-term damage.

Tips For Preventing Moss & Algae From Growing on Your Roof

The following tips can help you keep moss and algae from taking up residence on your roof.

Eliminate Moss & Algae ASAP. If you already see green and/or blackish growths on your roof, it’s important to remove them as soon as you can. In the right conditions, mold can grow pretty fast and this growth directly relates to the rate at which roofing materials decay. Established moss growths can be manually removed. Then, a thorough wash and the application of a bleach-water solution can be applied to remove the rest.

Moss growing on roof
How do you prevent moss from growing on your roof?

Unless you’re familiar with ladder- and roof-safety, professional moss and algae removal is often the safest and most efficient way to eliminate these offenders from your roof.

Trim Overgrown Tree Branches. Moss and algae require a moist environment. This is why we typically see the largest infestations accumulating in the shady areas created by overgrown tree limbs. Hire a certified arborist or professional tree trimmer to keep mature tree branches in check. Trimming them back and away from your roofline will help prevent moss and algae on the roof and will also prevent roof damage from fallen limbs and branches.

Keep Gutters & Downspouts Clean & Clear. When gutters and downspouts are full of debris, water has the chance to accumulate for extended periods. During the rainy season, this can lead to days or weeks of overflow, causing water to spill over and soak into roof and eaves materials. As long as temperatures are warm enough (about 35°F to 80°F), the ever-present moisture provides a perfect environment for moss to settle in.

Inspect gutters and downspouts at least twice a year to remove debris and make sure water is flowing through them as designed. Clear any clogs immediately to prevent water damage and repair any rusted, split or corroded gutter/downspout runs as soon as you can.

Use Strips of Zinc Flashing. Remember we said that moss and algae use organic materials as a food source? Thin strips of zinc flashing (copper and lead flashing work as well) can be installed underneath rows of shingles where moss and algae are the most prevalent. Clean the roof first to eliminate any current moss or algae. Then, apply the strips as per the manufacturer’s directions. Always contact your roofing manufacturer and apply the strips as per their instructions to avoid violating your warranty.

Always use a safe ladder and climbing practices while performing work on a roof. If this is not your area of expertise, hire a professional roof cleaner or roofing contractor to do the work for you.

Need the help of a professional to clean your roof, gutters, and/or downspouts and/or to prevent future moss and algae growth? Contact Proman WC at 425-908-9121 or 510-478-4880. Don’t forget to ask us about our 15% discount for new customers.