The True Culprit
Gloeocapsa Magma bacteria is the true culprit that causes black streaks on roofs and many other exterior surfaces. Other forms of growth can be found in union with this bacterium, including mold, fungi, algae, mildew, lichen, and moss. These organisms copulate in warm, moist environments. This damaging roof bacteria results in organic growth that lifts, separates, and decomposes shingles. Additionally, roofing surfaces are made with materials that are metabolized by these micro-organisms. Most shingles contain limestone fillers that algae, mildew, and bacteria will use as a nutrient base.
Four Areas of Roof Decomposition
1. Algae and fungal filament root systems cause shingle cracks, turning and swelling.
2. Asphalt Shingle roofs break down because algae and fungi have a hunger for their limestone fillers. Limestone contains phosphates and is an excellent source of nutrients for algae and fungi. Also, as the acidic waste created by the fungus metabolizes, it deteriorates the shingles.
3. Because TPO membrane roof systems are uneven, they are especially susceptible to organic growth and waste due to pooling in low areas.
4. Asphalt tiles are also susceptible to further break down because of excess heat caused from the darkening of the shingles. The darker the shingles get from algae streaking, the more heat they absorb. This excess heat dries the shingles and prematurely ages them.