What is mossy zinc

How do I remove moss from my roof?

The bleach mixture is diluted so that it does no harm. I've used it myself at least a couple of times to kill accumulated algae.

You can also use things like Oxy-Boost and Stain Solver, a bleach substitute that I believe contains some hydrogen peroxide. It also works against light moss and algae, but may be less harmful to the plant life below.

It is even more important to determine the source of the moss. Roofs that collect moss are too shady under tall trees that keep them from drying out. You may need to open things up a little, but enough to let them dry out. Yes, these trees are a natural source of air conditioning, but trees tend to grow. So cut off any branches that protrude above the roof. Cut out a few others to let the sun in.

For roofs with little green it may be sufficient to put zinc strips on top. The zinc escapes and keeps the roof free from accumulations of moss. There are also shingles with a moss-inhibiting additive that prevents moss from growing. Copper strips should work too, and copper lightning bolts are readily available. I even read that you can glue copper pennies (use silicone) right under the edge of the top row of clapboards. They're mostly zinc anyway.

If the moss has built up a lot, the problem is that your roof will likely need to be repaired because it has been too wet for too long. The shingles will need to be stripped off and replaced, but likely the roof deck is soft and needs mending too. This can best be judged by a professional who will carefully inspect the roof.

Fiasco laboratories

I also saw bare copper wire stretched between two screws over a roof, one just below the summit and one halfway up. Over the years, just enough copper oxides are leached to knock down the moss.