Excessive moisture can significantly promote algae growth on asphalt shingles. When there is a high level of moisture present, it creates a favorable environment for algae, mold, and other fungi to thrive. These organisms can cause visible discoloration and staining on the shingles, leading to aesthetic issues as well as potential long-term damage if the growth is left unchecked.
Algae usually thrives in warm, humid climates, and asphalt shingles can provide the necessary organic material that algae uses as a food source. This not only affects the appearance of a roof but can also contribute to the deterioration of the shingles themselves, potentially shortening their lifespan and effectiveness in protecting the home.
Other options relating to flexibility, adhesion, and warping do not accurately describe the impact of excessive moisture on asphalt shingles. While excessive moisture may affect these characteristics in various ways, it primarily correlates with promoting the growth of algae, which is a direct consequence of moisture presence.