Benefits of being repairable:
- Avoids roof replacement costs.
- Avoids use of natural resources.
- Can prolong roof life indefinitely.
Here we have the roof of Mr. Bechtel, whose family built Hoover Dam, the Oakland Bay Bridge, and many of our nuclear power plants. Notice his roof is wood shake. It is located in some of California's most expensive real estate: Atherton. In the top photo, you can see the light shakes. Those are the shakes that have been replaced. In the bottom photo, the finished roof has been power washed and appears new again. It is treated with a clear fire retardant wood preservative.
Here we are looking at the repair of a cement tile roof, from the vantage point of a wood shake roof.
Ortho guide for homeowners states "Modern wood preservative will greatly extend the life of cedar roofing."
This Old House Magazine, July - August 2001 issue. Norm Abram and the U.S. Forest Products Laboratory suggest you apply a "UV-inhibiting, water-repellant, wood preservative" but "avoid sealants, waterproofers, and paints...they lock in moisture and invite rot." By the way, the same article says Norm Abram has a wood shingle roof on his new home.
Wood shows rot on underside (golden color) while being preserved on top side due to application of oil-based wood preservative. This demonstrates how using a water proofing agent invites rot on the underside of the shake.
For more information please see the Cedar Bureau for how to care for a wood shake roof here.
Two problems attack wood shake roofs: ultraviolet radiation and organic rot. For ultraviolet radiation, a wood preservative that protects against UV rays is recommended. For organic rot, copper strips can be placed along the roof ridges so rain can wet the copper and transfer the copper to the wood material and therefore kill the organic rot process. Copper napthenate, a toxic solution, can also be used.