Algae grows on your house because it finds the perfect environment for survival and reproduction: moisture, shade, and a food source.
Here's a more detailed breakdown:
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Moisture: Algae thrives in damp environments. Areas of your house that are frequently exposed to rain, dew, or condensation are prime locations for algae growth. These areas are often found on the north side of the house (in the Northern Hemisphere) where sunlight is limited, or under eaves and overhangs that trap moisture.
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Shade: Direct sunlight can be harmful to some types of algae. Therefore, they often flourish in shaded areas where they are protected from intense UV radiation.
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Food Source: Algae, along with mildew and mold, feed on organic matter. This includes:
- Dirt and Dust: Airborne dirt and dust particles accumulate on your house's siding, providing a readily available food source.
- Sugars: Sugars, especially those that occur naturally in pollen and plant sap, are particularly attractive to algae, mildew, and mold.
- Siding Materials: In some cases, algae can even feed on the siding material itself, particularly if it contains organic components or if it's not properly treated to resist microbial growth.
Factors that exacerbate algae growth:
- Humidity: High humidity levels create a consistently moist environment, encouraging algae growth.
- Proximity to Trees and Vegetation: Trees and shrubs can contribute to shade and moisture retention, as well as provide a source of organic matter (leaves, pollen) that algae can feed on.
- Poor Air Circulation: Areas with poor air circulation trap moisture and create favorable conditions for algae to grow.
- Infrequent Cleaning: Regular cleaning of your house's exterior can remove dirt, dust, and other organic matter, depriving algae of its food source.
What you can do to prevent algae growth:
- Regular Cleaning: Wash your house's exterior regularly with a cleaning solution specifically designed to remove algae, mildew, and mold.
- Improve Drainage: Ensure proper drainage around your house to prevent water from pooling and creating moist conditions.
- Trim Vegetation: Trim back trees and shrubs that are close to your house to improve air circulation and reduce shade.
- Consider Algae-Resistant Siding: If you are replacing your siding, consider using materials that are resistant to algae growth.
By addressing these factors, you can significantly reduce or eliminate algae growth on your house.
