black spots on the roof. can you tell me what is the cause of this? have lived in this house 12 years and have had no problems. what can you do to clean this?
This type of staining (algae as the other posters have said) will usually only happen on the North facing surface of the roof. Same with condensation on your car glass. Suprisingly, the North facing ... read more
Scott,
The easiest thing to do is check in the attic and look at the sheathing. If there is any mold growth, you can tread it with a proper mildewicide and make sure that the fan ducting is extended ... read more