Cleaning & Maintaining Cedar Shakes

Periodic Cleaning

As mentioned in another article, you must keep your roof clean and free of debris. Cedar roofs need vast amounts of air to keep them dry. Trim overhanging tree branches so that there is at least a 3 to 4 foot area above the roof. Don't let overhanging branches rub the roof or hang too closely. They simply inhibit evaporation of rain water or morning dew.

Moss Control

Moss is a major problem on shaded cedar shake roofs. Its presence can significantly shorten the life of your roof. Copper and zinc have proven to be very effective at stopping the growth of moss on cedar roofs. A copper ridge flashing may be all it takes to keep your roof clear of moss. You can also install zinc strips which expose 2 inches of metal at certain intervals as well. These strips release molecules of zinc with each rainfall. The strips look a little funny when first installed, however, they weather and take on a dull appearance in short order. They are a tremendous investment. Don't underestimate their value.

Cleaning a Dirty Roof

There are several ways to clean a cedar roof. Power washing with a pressurized machine is very effective. However, if an untrained person performs this procedure, shake damage, leakage, wood erosion, etc. are REAL possibilities.

When using water on a roof, either from a hose or a power washer, NEVER spray up the roof. Roofs use gravity to keep your house dry. Spraying water up the roof is not natural. By doing this, you will drive water up under your shakes. Drive water far enough and it will leak into your house. I guarantee it!

Many past publications have promoted the use of a cleaning solution that contains either regular or commercial strength bleach (sodium or calcium hypochlorite). These forms of bleach can actually harm your cedar shakes. They can cause cellular damage similar to that caused by UV light. They also will remove (bleach out) the natural extractive chemicals which give cedar its beautiful color tones. A better solution is to use oxygen bleach. It will clean your cedar shakes with no problems. It will not remove the color and it is environmentally safe, unlike standard bleaches.

Sealing & Preserving

After cleaning your roof, let it dry. This may take 2 to 3 days. Then, apply whichever product you have chosen exactly as it says to doon the label. Do not become your own testing laboratory. Manufacturers have gone to great lengths to determine application techniques and quantities. If you deviate from their instructions, you only stand to hurt yourself.

Using the proper type of application equipment is essential. If a product says to use a power airless sprayer, don't try to substitute a pump garden type sprayer. Use common sense!

Roof Safety

Roofs are dangerous places. I have fallen off several and lived to tell about it. Moss covered cedar shake roofs are like tilted, elevated ice skating rinks. Need I say more? Add water to these roofs and they become practically impassable.

Cleaning and sealing cedar shake roofs should not be attempted by a novice homeowner. Serious injury and death are very real possibilities.

Give serious consideration to hiring this job out. Let a seasoned professional clean and seal your cedar roof. Be absolutely sure this individual has worked on such jobs and is insured with Worker's Compensation. Make sure they attach a copy of their current certificate, indicating paid up coverage, to your contract. Don't underestimate how dangerous this job can be.

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