Causes of Roof Deterioration
WHAT CAUSES YOUR CEDAR SHAKE ROOF TO DETERIORATE?
It gets “OREGONIZED.” When wood is exposed to the effects of
sunlight and moisture, its surface begins to change. This change is both
physical and chemical, and is commonly called weathering. The color will
change first. The initial change from reddish brown to silvery gray is
the result of the ultraviolet rays from the sun. This usually happens
fairly quickly – well within the first year. Gradually the roof
will take on a darker gray color. This indicates that your roof is being
colonized by microfungi. Your roof is steadily becoming “OREGONIZED.”
As the roof continues to age, the surface and sharp edges are eroded by
abrasive particles carried by wind and water, and by continued exposure
to heat and cold. Wood destroying organisms continue to slowly degrade
the shingle’s surface and edges. The roof no longer looks new. Debris
from trees may be accumulating in the valleys and between the shakes.
After each rain, these areas will remain moist longer. Because of the
moist conditions, other plants soon begin to grow, primarily lichens and
mosses. Your roof is now “OREGONIZED” and its deterioration
will rapidly accelerate.
Moss and fungus growing on your roof does double damage: (1) During a rain,
it retards the shedding of water, which promotes leaks and (2) After the
rain stops, it prevents the surface from drying, which further encourages
the growth of wood-rotting organisms.
Leaves, needles and other debris which is allowed to accumulate has these
same two harmful effects. In addition, the debris increases the fire danger
to your roof. There are several ways you may choose to deal with this
debris and I would be glad to go over them with you. The point is, you
must deal with it or your roof will rot away at a surprising rate.