Question - I recently purchased a house with cedar shingles. I was told that I do not have to do anything to my roof. I have also been told that the solution to treat the roof ranges from a traditional waterproofing solution to a a solution that has to be professionally applied. Could you please set the record straight? M.R.H.
Answer - There are two types of cedar roof coverings: a cedar "shingle," which is a thin, uniform, machine-cut shingle, and the cedar "shake," which is thicker and has a more uneven surface.
Shakes are made by hand or by mechanically splitting the wood, thereby giving it its uneven texture. The life expectancy of a cedar roof is 30 to 40 years. However, low-quality shingles have been known to fail in as little as 15 years.
Two factors greatly affect both shingles and shakes. Too much sun will dry out the wood, causing the shingles to become brittle and leading to splitting or curling. Excessive shade produces a damp roof where moss and rot can form.
It is important to protect the wood from water penetration.
Chemicals should be applied by a professional familiar with the safeguards associated with their use.
If the roof is in good condition, homeowners can apply protective products such as CWF or Thompson's Water Sealer. Tests on cedar roofs conducted by the Texas Forest Service suggest a simple cure is to apply a solution of 1 percent Cunapsol in water. Cunapsol is available from ISK Biotech, 6075 Poplar Ave., Suite 306, Memphis, Tenn. 38119; phone toll-free (800) 238-2523.
The solution can be applied with a Hudson-style garden sprayer.
It is recommended that wood roofs be treated every five years.
For more information, contact the Cedar Shake and Shingle Bureau, 5151 116th Ave. NE, Suite 275, Bellevue, Wash. 98004-5294; phone (206) 453-1323.