Do you spot black streaks across your roof? Are those streaks a sign of algae or mold growth? Are the two equally as bad? We’ll explain the difference, how to distinguish the two, and how to treat them.
Algae is simply a moss-like plant form that thrives under moisture and sunshine. It spreads through airborne spores and is common among residential roofs made from asphalt shingles. Algae is also much more common than mold, and that’s a very good thing. While algae on a roof can be an eyesore, it’s not dangerous, nor does it cause damage.
Mold, on the other hand, is a much greater cause for concern. Black mold is especially dangerous as it releases toxins that can cause respiratory issues, ranging from headaches to severe coughing fits.
Both algae and mold manifest as black streaks, so a visual inspection from ground level is not enough. Mold thrives under damp and poorly ventilated conditions. Inspect your attic and crawl spaces for signs of mold. If everything appears okay and black streaks manifest solely on the roof, then it’s likely the more harmless algae.
Treatment options for both mold and algae are more or less the same. Prevention is the best step; we recommend regular pressure washing for the roof. This is best done by a professional; using too much pressure can damage the roof, and not using enough gives the roof nothing more than a light wash.
Both residential and commercial roofs are susceptible to algae and mold growth. Urbizo Bros Roofing can restore roof surfaces. We also provide other home services, such as gutter installation, which prevents water from collecting and creating the damp environment conducive for algae and mold growth.
Edited by Justin Vorhees
Quality roof replacement & repair in Edmonds, Seattle, Lynnwood,
Mill Creek, Mercer Island, Mukilteo & South Everett