Your roof has a lot to deal with. The sun beats down on it, the rain drenches it, the winds whip it and the snow freezes it. It is no wonder that discoloration can happen. Common reasons for roof discoloration include algae, rust and asphalt bleed through.
Greenish black colored algae are most common on north-facing roofs that don’t get a lot of direct sunlight. Water from rain can stay strapped on this side of the roof and it encourages the growth of algae. It is more than just unsightly; it can damage asphalt roof shingles.
Manufacturers are adding zinc and copper to newer shingles to discourage this issue but if you have older shingles you may need to contact a roof construction company.
Metal roofs are prone to this type of roof discoloration. Even if your roof is covered with asphalt shingles, flashing and other things mounted on your roof may be made of metal and suffer from rust. These issues can be abates with several different products and are best applied by a professional. A metal roof can be painted with a couple of coats of paint to protect it from the elements.
Asphalt bleed through
Exposure to the elements can cause the black asphalt to rise to the surface and run down the roof in a very unsightly manner. This can be a sign that your shingles are reaching the end of their life or that they are of poor quality. Calling in the professionals can help you decided if it is time to replace an aging roof or replace low-quality shingles.
Contacting a qualified construction company is the best way to deal with all three of these roof discoloration issues. Discoloration can cause issue that will lead to roof failure and water damage can be expensive to correct. It is much wiser to be proactive and fix the issue before it becomes really serious.