Mossy Roof
What you need to know
Moss on roofs in Portland is a very common problem that can shorten the life of the roof and lead to costly repairs. What's the problem? Moss can actually degrade the shingles by breaking down the fibers that hold shingles together. As moss continues to grow under shingles they lift the shingle which causes them to crack while also exposing them to wind damage. If that isn't enough they also hold moisture on the roof which increases the chances of having a leak or rotted wood under the singles. What's the solution? If moss starts growing on a roof you need to get rid of it quick. One of the most environmentally friendly ways is to spray the roof with Oxygen Bleach. Oxygen Bleach is initially toxic but degrades quickly to mostly harmless elements within an hour. If you can spray it on a roof and keep the roof wet for at least 30 minutes it will kill a lot of the moss and make it easier to wash off. This should be done once a year. |
Once the thicker moss has been killed you can have a professional install zinc strips under the ridge of the roof. As it rains, a little zinc will wash off and run down the roof. Zinc is toxic to moss.
Look at the above picture. The flashing (metal pieces) around the sky lights are coated in zinc. As you can see there is no moss where zinc is being washed down the roof. Zinc is very effective and once installed can passively protect your roof for many years.
Look at the above picture. The flashing (metal pieces) around the sky lights are coated in zinc. As you can see there is no moss where zinc is being washed down the roof. Zinc is very effective and once installed can passively protect your roof for many years.