Common Causes of Roof Stains

What causes roof stains? Most are caused by a short list of common roof issues. These include algae growth, soot buildup, rusty flashing, and defective roof tiles.

So, what’s causing your roof stains? Well, that depends.

What do the stains look like, spots or streaks? And what colour are they? Are they green, black, red, dark grey, or something else?

Whatever your roof stains look like, we’re going to help you identify the cause with this guide. Look through these common roof stain offenders to find the issue that matches the look of your stains. But, afterward, make sure you call for professional help to solve the problem.

1. Soot Buildup

Soot buildup can accumulate on your roof if you don’t have your chimney or roof cleaned often enough. This will usually appear as black stains around your chimney and beneath it following the slope of your roof.

Besides getting a good cleaning, you should also have your roof and chimney inspected to make sure your chimney is working properly. The stains could indicate improper venting or some other chimney problem.

2. Algae

If you live in a humid area or there is moisture constantly sitting on your roof, algae can start to grow. If the stain is green, a close look should indicate whether it’s algae or some other biological growth, like lichen and moss. Black algae stains are also very common.

Fortunately, none of these are typically harmful to your roof, only ugly. A professional roof cleaning will take care of this.

3. Rusted Metal

Reddish/brownish stains usually indicate rust. This is a problem you should worry about.

It’s most likely due to your chimney flashing getting rusty. But, that’s beside the point.

It’s dangerous for any part of your roof to be rusting. So, get it checked out by a roofing contractor right away.

4. Debris

Leaves, branches, and other debris deteriorate as they sit on your roof for a long time. This leaves behind dark, dirty-looking stains.

Even worse, these dirty piles trap moisture on your roof that can eventually cause it to decay. It’s very important that you have such debris cleaned off of your roof right away.

5. Extractive Bleeding

Lastly, extractive bleeding is an unfortunate side effect of cheap, faulty roofing. It’s the result of a product defect in which the colour bleeds out of the roofing shingles and streaks its way down your roof.

If you can, contact the roofer who installed the shingles to fix their shoddy roofing job for free. Otherwise, contact a professional roof cleaning service and/or have the roofing replaced.

Get These Roof Stains Inspected by a Professional

So, did you find out which issue was causing your roof stains? If so, give us a call so we can address the problem before it gets worse.

On the other hand, maybe this list does not provide the answer you were looking for. Don’t worry—we can help with that, too!

Just call the number at the top of this page or fill out our online contact form now. We’ll assess your situation and get you the help you need right away.