Black streaks. They are the bane of my existence when listing my clients’ homes for sale. Those stains are actually dead cells of tiny, pesky microscopic bacteria that thrives in humid climates like ours in Northern Virginia. If you got ‘em, here’s a cost-effective way to reduce or even eliminate them:

Find a season handyman to get up on your roof when it is cool, e.g. early in the morning or during a cool fall or spring day. To help ensure it’s done right and the first time, apply a mixture of equal parts water and oxygen bleach (note:  NOT chlorine bleach because it can kill vegetation below). Have your helper spray it on and then scrub it with a basic scrub brush. This process should restore the roof to its original look. See accompanying photo courtesy of

Here’s an option for those replacing their roofs and to eliminate them from the start. Place a strip of copper across the apex of the roof. When rain washes over it, it transports a residue that fights the bacteria. Voila, no washing or scrubbing should be necessary. The copper will weather quickly to an attractive bronze or green color adding a distinctive touch to your homestead.

Read more about this from a recent edition of the Chicago Tribune’s Homes section.