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Zinc Strips on Mossy Roof, Four Years Later

By In Zinc Strips On July 8, 2014

In November of 2011 I wrote a blog post about using zinc strips to prevent moss from growing on the roof, or possibly to kill moss.  I conducted a fairly long-term experiment by installing zinc strips on a moss-covered garage roof, and showed before and after photos after the zinc had sixteen months to work its magic.

The results were much better than I had expected.  The first photo, showing the untouched roof from July of 2010, showed a lot of moss growth.

Mossy roof before

The next photo, from November of 2011, showed far less moss.  I used a leaf blower to clean the roof off before taking that photo.

Mossy roof after

It’s been about four years since I installed that zinc strip, and the shingles are going to be replaced soon, so I’m showing a final follow-up photo before that happens.

Mossy Roof four years later

As you can see, it looks like there has been some new moss growth.  Why?  I don’t know.  Perhaps the zinc strips lose some of their effectiveness over time?  Maybe the record amount of rainfall we’ve received this year has made the moss growth worse.  I’m not sure.  The bottom line is that zinc strips certainly help, but it’s tough to say whether they’re worth the extra money.

To read the original post, click here: http://www.structuretech1.com/2011/11/zinc-strips-prevent-moss-growth-on-roofs/

Author: Reuben SaltzmanStructure Tech Home Inspections


About the Author


Reuben is a second generation home inspector with a passion for his work. He grew up remodeling homes and learning about carpentry since he was old enough to hold a hammer. Reuben has worked for Structure Tech since it was purchased by Neil in 1997, and is now co-owner and President of the company.


  • Dan 3 YEARS AGO

    Well, that explains why I have those strips on my roof...we bought a house with architectural shingles on it and I wondered about those. Anyway, the 2014 moss growth may be due to the unseasonably wet AND cool spring/summer we've had. Or, as you said, they may lose their effectiveness due to surface oxidation. I am leaning to the former because I've seen roof vents on shingles 10+ years old still creating the mildew (black stuff) growth-free wake below them.

  • Mohammad 3 YEARS AGO

    Very useful information.