Lichens are a fungus that grow symbiotically with algae, resulting in a composite organism that characteristically forms a crust like or branching growth on shingle granules. Lichens put out root-like tentacles that penetrate deep into the shingle’s organic, oil base for nourishment, eventually ruining them by creating dark spots, or pockmarks where they grow. It’s extremely important to have lichen colonies removed professionally via soft washing to stop the damage in its tracks and prolong the life of your shingles and roof.
Moss growth with its shallow root system keeps the roofing materials damp for extended periods of time and this moisture promotes wood rot and can and does erode asphalt shingles. Moss, like lichen colonies, is quite damaging to shingles and some of the granules underneath the moss may be gone. This will be evident if once the moss is removed. the portions of the interior mat of the shingle are visible. It’s important to have moss professionally removed from your roof in order to extend the life of the shingles.