Why Are My Shingles Discolored?

Shingle roofing is a fairly durable roofing option, but as is the case with exterior material, it wears away against the elements of nature. Sun, wind, and rain combine to create stress on your shingle roofing, causing a number of effects and issues.

Discoloration is one of these effects. Shingle roofing discoloration can happen anytime throughout the roof’s lifespan, and in many cases it isn’t an issue whatsoever. There are other cases, however, where discoloration is a sign of damage.

Here are 3 reasons why your shingle roofing could be discolored:

1. Shingle Roofing Algae or Mold

If you’re seeing dark, greenish or black streaks on your shingle roofing, then you could have an issue with aglae. Algae stains tend to form on the north-facing side of the roof and are more common in humid, damp areas. Since this side of the roof is exposed to less direct sunlight, water from rain or the humid conditions can become trapped in various sections of the shingle roofing and develop into green or black algae streaks. Most of the United States falls under the “humid climate” category, so keep an eye on your roof for any signs of growth. If one occurs, clean it off immediately, and if it returns, call a professional for help.

2. Rust

If your shingle roofing is made out of metal rather than asphalt, then the discoloration you see could likely be rust. This tends to be dark red or brown discoloration. If you see any of this type of discoloration, be sure to address the issue right away since mold could be a sign of a leak.

3. Asphalt Bleed-Through

Asphalt shingle roofing that has reached the end of its life tends to result in black streaks. Over the course of their lifespan, asphalt shingle roofing is exposed to many environmental extremes that cause them to deteriorate. Part of this deterioration process is the surfacing of black asphalt pigments that often run off in streaks. If this is your issue, you should consult a roofing professional to determine if you need a roof replacement. 

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