From the past to present day many cleaners use what is called the 3 step process for cleaning a cedar roof.
Sodium PercabonateÂ doesnâ€™t clean well and requires the use of pressure to completely clean the roof. Thus the use of a pressure washer which is to high (500 to 1000 psi) of pressure and will damage and erode your cedar shakes. Common sense indicates you would not want pressure of any form used on your wood roof. The downfall to the use of sodium percabonate is that it takes pressure to remove the solution.
Oxalic Acid as a brightener solution is a poisonous, crystalline acid used in many industrial purposes including rust removal and bleaching. It is both toxic and caustic. It also requires the use of high pressure to properly remove.
Staining, Sealing & Waterproofing. You can stain a cedar or wood roof to take on different hues or tones. Other than cosmetic staining has no true benefit. Sealing is the last thing you should do to a cedar or wood roof as they need to breathe or expand and contract with the weather conditions, thus the spacing between the shakes. Waterproofing has limited effectiveness and has a short shelf life.
Simply speaking cedar shakes or wood roofs should stay in their natural form as when they were installed. Cedar does not decay in and of itself. Only moisture and different infestations will decay cedar. Cedar does weather and needs to be maintained to last there designed life span. The only maintenance a cedar roof needs is a good cleaning every 5 to 10 years which is subjective on tree cover, moisture and weather condition.
Cedar is a natural insulator against the environment; competitors can’t come close to the thermal efficiency of wood. In fact, cedar has twice the thermal resistivity (R-value) of asphalt, 5 times that of slate, 8 times that of concrete, and hundreds of times that of metal and aluminum.
Cedar roofs don’t decay, but they do weather. It has natural preservatives that resist moisture, decay and insect damage. Although in warm, humid climates and on heavily shaded roofs, algae, moss, mold, mildew, lichen and fungi’s will grow, because these organisms retain moisture the cedar will decay in time if not maintained.
When new the shakes and shingles display the natural honey and cinnamon tones, and will later mature to a seasoned and distinguished-looking silvery gray when properly maintained.
If the shakes or shingles display a brown/dark brown to black tones, these are signs of harmful organism infestations and they need to be cleaned. The same applies to moss, mildew, lichen and fungus.
With a proper cedar roof maintenance program a cedar roof will last anywhere from 40 to 60 years which is also subjective to conditions and if maintained.
There is an alternative to the 3 step process for cleaning cedar shakes or wood roofs and for roof cleaning.
It is a 1 step process: Cleaning. In todays roof cleaning industry the process or equipment used to clean a roof is what is call non-pressure or Soft Wash process. The solution is applied with a 12 volt pump system with the average pressure of 60 psi and the rinsing process is done with a simple garden hose pressure or about 40 psi. Watch the videos to your right on how the process works and the equipment used.
As to the cleaning solution there is also an alternative that is non toxic and caustic. The cleaning solution is a Citric based cleaning solution ( not citric acid) that contains algaecide, mildecide and fungicide. Though cedar shakes only have 3% oil content when installed, there is a water base oil in the solution that helps rehydrated the shakes. This solution is not for sale as it was developed personally. To see results go to:http://cedarshakesroofcleaning.com/cedar-roof-photo-gallery/. Also see: http://cedarshakesroofcleaning.com/category/customer-reviews/.
On average the cost of a cedar shakes roof cleaning should be about $0.50 a sq. ft. or less than 10% of replacement cost.
So when considering having your cedar roof cleaned do your research. There is a difference between someone who can clean a cedar roof and someone who is a cedar roof cleaner.
This is my sole opinion based on my research and years of experience with cleaning cedar shakes roofs.
Bruce Sullivan, Owner
Sullivan Roof Cleaning, Inc
Service all of Iowa and the Greater Midwest