It's pretty fascinating that a zinc strip can so easily avoid moth growth. As you said, moss can cause very serious problems for the roof and the structure underneath. Water damage can greatly weaken the integrity of the wood. When we lived in Washington we had to keep a careful eye on our roofs because of the extra moist environment. Any sign of mold or moss required immediate attention.

That's scary that mold spores can spread so easily. I can see why it would be important to act fast if we saw any moss on the roof to prevent anything like that from spreading. Maybe next time we get our roof repaired, we will switch to shingles that won't let moss grow on them.