Shake roofs have been used in America for hundreds of years. Early builders made them from whatever kind of wood was available in the area, whether it was cedar, redwood, oak, cypress, pine or spruce. Today the most commonly used wood for shakes is cedar. It's long lasting, resists rot, and can be left untreated to weather to a silver gray color or treated to maintain it's natural golden red color.
To many people shakes and shingles are basically the same, but, even though they are both made from natural wood, there are differences in way they are made and their final appearance. The essential difference is shingles are machine sawn and as a result are smooth tapered boards. Shakes on the other hand are actually man made, using a tool called a "froe" to split the wood into thing pieces. This splitting technique is what gives shakes the rough surfaces that many architects and homeowners find so attractive.
Installing and Caring for Shake Roofs
Shakes should only be installed using galvanized, aluminum or stainless steel nails. Regular steel nails will react chemically with the cedar shakes and end up with unattractive black stains running across the surface.
The shakes are usually installed starting at the bottom and working up. Each shake is fastened with two nails near the top edge. The next row of shakes is placed so it covers about half of the shake below and as a result, hides the nails. This process is repeated row after row, until you get all the way to the top.
Once installed, shake roofs need a certain amount of maintenance to retain their attractive appearance. The roof needs to be kept clean and free of debris as well as ensuring overhanging branches are well away for the roof itself. If the branches are too close, they will shade the roof, which will tend to keep it damp and encourage the growth of moss on the shakes.
Actually cleaning a shake roof can be done with a power washer and a combination of water and oxygen bleach. This mixture will clean the dirt from the roof, but not bleach the color out of the cedar. As a bonus, the oxygen bleach is environmentally friendly. When using the power washer work from the top down, not from the bottom up. If you spray from the bottom, you will be forcing water in under the shakes and quite likely will end up with a water leak inside the house.
Cedar shakes provide a beautiful architectural link with America's heritage, but remember that beautiful or not, roofs are dangerous. If you are going to be working on your roof take proper precautions and work slowly and carefully. If you have any doubts or concerns about your own ability to do the job safely, hire a professional roofer.