Roof Cleaning Issues-Get Answers about Stains
| Why Are There Black Stains on my Roof? | Algae is the primary culprit behind the black streaks on your shingles. You’ll usually find it close to the ridges. |
| Where Does Algae Come From? | Algae spreads through flying spore thats usually come from algae growths on neighboring roofs. |
| How Does Algae Grow and Expand? | Moisture and the right temperature range are the two things algae needs the most. Unfortunately, both of those are in high supply in the Western Coastal areas. North-facing roofs are known to be particularly susceptible to algae growth. |
| How Can I Protect My Roof? | 1. Algae-resistant shingles can be installed as a replacement. These shingles are more resistant to algae growth.2. Pressure cleaning is very effective at removing algae, and additional treatments can be applied to the roof after the cleaning to inhibit new growth. |
| What Shouldn’t I Do? | 1. Aged shingles should NEVER be power washed. This rough treatment can damage your roof. Safer steam cleaning is the better option.2. You should never attempt to walk over your roof without the proper fall protection. If you’re not sure what that is, then you should let a professional handle the job for safety. |
The Facts about Your Roof and The Things Growing on It | ||||
|---|---|---|---|---|
| Question | Algae | Fungus | Moss | Lichen |
| What Does it Look Like? | It appears as green and black stains. It may be called “Gloeocapsa Magma”, “Cyanobacteria”, or “Blue-Green Algae” | It appears as spongy green clumps. It may look similar to mold and mildew. | If it’s green and spongy, but not algae or fungus, it’s likely moss. | Lichen typically appears in a star position in a range of colors including orange, yellow or white. |
| What Does it Need to Grow? | Algae prefers inorganic food sources like asphalt fillers. To thrive, it needs moisture and cool temperatures | These growths get their food from the soil. They also need the right temperature range to thrive | ||
| Where Do These Growths Occur? | Algae occurs all over the nation, particularly on in areas with high humidity | These also like high humidity, but they’re particularly vigorous under shade or tree cover. | ||
| Typical Roof Exposure? | Roofs that are facing the north are the most susceptible. | Any roof is susceptible to these growths. | ||
| Impact on Roof? | Algae is not dangerous to your roof, but does look disgusting. | These growths can worsen the appearance and defenses of your roof. It should be removed immediately. | ||
| Do Algae-Resistant Shingles Work? | Yes | While effective against algae, these shingles are not effective against these growths. | ||
| How Do I Make it Go Away? | Using an Anti-Algae solution on the roof is an effective solution | 1. The clumps can be removed, which will hinder growth.2. Anti-Algae solution may be effective in some cases. | ||
Algae: Facts & Fiction | |
|---|---|
| Fact: | Algae spreads by the use of airborne spores. The spores can travel easily between the roofs of nearby houses. |
| Fact: | Algae can survive in many different conditions and climates, even extreme ones. |
| Fact: | The color of the algae comes primarily from the dark green sheath that each cell produces to protect itself from the sun. |
| Fact: | Mold can be inhibited by copper and Zinc. Copper is much more effective against algae than zinc. |
| Fact: | Algae gets most of its water from dew. |
| Fact: | Algae can survive long dry and hot periods, though it is dormant during the winter. Algae can be difficult to remove due to the material it secretes on surfaces. |
| Fiction: | Copper is immediately effective against algae. FACT: The Copper poisons the algae over time. |
| Fiction: | Algae is a fungus. FACT: Algae is in the Eubacterial family. It is not a fungus. |
| Fiction: | Adding copper ridges to your roof will kill any colonies there. FACT: Copper has never been demonstrated to completely destroy a colony. |
