Q: I have a cottage in the Adirondacks which has been newly covered with unstained cedar shingles. However, in this damp climate such untreated shingles tend to become dark brown instead of a bleached gray. It has been suggested that the shingles might be treated with a household bleach which will destroy the organisms which cause the black-brown discoloration. How can I achieve a light-gray hue to the shingles? Harvey W. Noordsy DeWitt, N.Y. A: The Red Cedar Shingle and Handsplit Shake Bureau in Bellevue, Wash., says that, if the cedar-shingle walls are weathered and have completely darkened over a period of years, the only satisfactory method it knows of is to return the wood to its original color by wire brushing (electric for speed) or sandblasting.
To achieve a light-gray shade on new shingles, apply a semi-opaque wood stain. As to applying a household bleach, experiment with it on a couple of shingles and see what happens.