Why We Install Zinc on Roofs to Prevent Moss
We came out to inspect a roof and immediately noticed something unusual — nearly three
inches of moss built up under the solar panels.
The homeowner had avoided touching that area because he was afraid of damaging the solar
array. A previous roof cleaner had refused to work around the panels altogether.
So the moss just kept growing.
Why Moss Is a Real Problem
Moss isn’t just cosmetic.I t traps moisture against the shingles. That moisture:
- Breaks down roofing materials
- Lifts shingle edges
- Shortens roof life
- Increases the risk of leaks
In the Pacific Northwest, moss can grow aggressively — especially in shaded areas and beneath
solar panels where moisture lingers. If it’s left alone long enough, it becomes structural, not just surface growth.
Cleaning Is Only Step One
We carefully cleaned the entire roof, including under the solar panels. But cleaning alone isn’t a long-term solution. If you remove moss without adding prevention, it comes back.
Why We Use Zinc
After cleaning, we installed zinc strips along key areas of the roof.
Here’s how zinc works:
When it rains, small amounts of zinc wash down the roof surface. Those particles inhibit moss
and algae growth naturally. It’s simple chemistry — and it works.
Zinc doesn’t damage shingles. It doesn’t require ongoing maintenance. And it dramatically
slows moss regrowth over time.
The Result
The roof is now:
- Clean
- Drying properly
- Protected against future moss growth
The biggest mistake we see is homeowners repeatedly cleaning moss without addressing why it
grows in the first place. Prevention is what extends roof life.
If you have solar panels or shaded roof sections, zinc is one of the simplest ways to protect your
investment.
Serving the Portland Metro


