If you're considering replacing your exterior roofing roofing material with cedar shakes, you've probably heard great things about the longevity and durability of cedar shakes -- all of which are true. Because these trees are native to the temperate rain forests than grow in the Pacific Northwest, British Columbia, and southeastern Alaska, their wood is biologically engineered to last for years. However, this doesn't mean that cedar roofing is maintenance-free -- it requires a little upkeep in order to remain durable and aesthetically appealing.

Following are four strategies designed to help extend the life of your cedar roof and keep it looking good for a long time.

Have The Cedar Shakes Installed Properly

Improper installation of cedar shakes can have a significant impact on how well the roof holds up over the years. Although cedar is less likely to warp than many other types of wood, it still needs room to breath, so be sure to leave a 1/4-inch airspace between shakes to allow for the natural expansion of the wood during wet weather. You should also use stainless steel nails to avoid rusting -- rusty nails will cause your cedar shakes to come loose and fall from your roof.

Keep Your Roof Clean

Even though cedar wood has a natural resistance to mold and mildew, these infestations can still develop if organic debris is allowed to build up on the roof's exterior. Fallen leaves and other vegetative matter should be removed from your cedar roof as soon as possible in order to prevent the creation of an environment that is conducive to fungal infestations. You should also make certain that you keep trees trimmed so that they don't overhang onto your cedar roof -- this creates an overshaded, damp environment -- a sure way to invite fungal spores, moss, and lichen to take up residence on your roof. To keep these organisms at bay, inspect your roof periodically for signs of their existence.

Cleaning your roof with a solution of three quarts of warm water, 1 quart of bleach, and 1 ounce of mild household detergent will help keep your roof free of mosses, lichens, mold, and mildew. This should be performed once or twice per year but should not take the place of a good professional cleaning.

Have It Professionally Cleaned Periodically

Having your cedar roof professionally cleaned once every six to eight years will also help ensure that it lasts for a long time. Professional roof cleaning companies have equipment and supplies that most homeowners do not have access to, meaning that they can remove tiny bits of debris and decaying material before they can grow into a major problem. Professional roof cleaners are also trained to notice signs of small problems before they become major, costly issues, such as single loose shakes with fungal growths beneath them.

Select Finishes With Caution

Certain types of finishes should not be used on cedar roofs because they will interfere with the natural ability of the wood to shrink and expand as a result of temperature and humidity fluctuations. These finishes include paint, varnish, and colored stains, so be sure to consult with your roofing contractor before applying any of these products. Your contractor may be able to recommend a finish that works particularly well for your given location. For instance, if you live in the fairly rainy city of Vancouver, B.C., you should consider having a clear, oil-based finish applied because it will act as a water-repellent. If you live in an area that experiences seasonal wildfires, your contractor will be able to suggest appropriate fire-retardant treatments for your cedar roof.

Taking proper care of your cedar roof will help ensure that it lasts for between 40 to 60 years.