Controlling and Removing Roof Moss

In parts of the world where there is substantial wet weather it is not uncommon to find moss, lichen and algae growing extremely well on roofs, decks, walkways and on outdoor structures (especially the side of a building that is shaded).

If you want to remove and prevent the reoccurrence of the moss, lichens and algae there are some steps that you can take that should be beneficial.

1. A power washer is an excellent tool to remove the growth of these plants.  However, a power washer can do a lot of damage if not used properly, especially on roofing materials such as asphalt shingles.

As with any chemical products always read the directions and warnings prior to using them.

It was believed that iodized salt would remove moss, however, it will corrode any roof flashing or other metal that it comes in contact with - and it does not control moss growth effectively.

One control method that does appear to work is to use a length of sheet copper on the roof ridge and if the roof is longer than 10 feet to add copper wire at intervals along the roof.  As it rains, copper ions are washed from the copper and flow down the roof, moss, lichens and algae will die when confronted with copper ions.

The copper ridge cap has no specific dimensions, 4" to 6" wide should be sufficient.  Flat copper material can be purchase from any metal supply house.  Tell them you want sheet copper for roofing - most suppliers will even cut it to size for you.

Bare #6 copper wire can be purchased at any electrical supply or most industrial metal houses.