A Homeowner’s Guide to Maintaining your Cedar Shake Roof
Part 2: Easy Routine Maintenance
In Part 1 of this series we discussed the ways your cedar shake roof can break down and weather due to time and neglect. Let’s now move on to routine maintenance. Keep in mind that I never recommend someone climb on their roof or clean their roof themselves. The dangers of falling and/or damaging your roof are too great a risk to take. It is always best to hire a licensed and insured professional.
A Few Words on Maintenance:
- Proper cedar roof maintenance starts with keeping your roof dry. If your roof retains water, it creates an inviting environment for wood-rotting fungi to grow. There are several things you can do to prevent this from happening.
- Remove all leaf litter, pine needles, and other tree debris that accumulates between the shingles, in the valleys, and around the chimneys, as this debris prevents the roof from properly shedding water.
- Remove overhanging branches that shade large sections of the roof. Shady areas do not dry as quickly as sunny areas.
- In woody areas, excess branches may restrict airflow to the roof, preventing the roof from drying as quickly as it should. You may want to consult with an arborist about pruning, trimming, or removing problem causing trees.
- It is also a good idea to keep tree branches from touching and rubbing against the roof. This rubbing can wear sweeping grooves into the surface of the shingles and loosen the fasteners, opening areas for fungi to grow.
- Look at the trees around your property. If you see excessive growth of lichens and moss, it means excessive moisture is present, and could be on your roof as well.
Hiring a Professional:
Since I do not recommend you climb on your roof yourself, you will want to hire a professional to clear off the debris. Make sure the professional does not use high-pressure washers. Cedar is a soft, low-density wood, and excessive or imprudent use of high-pressure systems can detach shingles or erode many years of wear in moments. Even though this will easily and quickly clean off the roof, you may have done irreversible damage to your roof in the process.
Damage Caused by Wood Decaying Fungi
Wood destroying fungus (fungi, plural) or wood decaying fungi, causes more damage to structures than all the fires, floods, and termites combined! Wood decaying fungus requires four fundamentals to survive which are oxygen, favorable temperatures, water and food. Fungus occurs generally when the moisture content of wood exceeds 20 to 30 percent, coupled with optimal temperatures (32 – 90 F), an adequate supply of oxygen and a suitable source of energy and nutrients.
Fungus is a plant that lack chlorophyll. Unable to manufacture its own food, it feeds off of cells in the wood. The fungus secretes enzymes that break down the wood into usable food. Fungi will significantly reduce the strength of the wood, if the condition continues over a period of time.
Two most commons types:
White Rot Fungi:
White rot breaks down all major wood components (cellulose, hemicelluloses and lignin) more or less simultaneously, and commonly causes rotted wood to feel moist, soft and spongy, or stringy and to appear white bleached. Wood affected by white rot normally does not crack across the grain and will only shrink and collapse when severely degraded. The strength of the infested wood decreases gradually until it becomes spongy to the touch and stringy when broken.
Brown Rot Fungi:
Brown rot primarily decays the cellulose and hemicelluloses in wood, leaving a brown residue of lignin, the substance which holds the cells together. Wood affected by brown rot is usually dry and fragile, readily crumbles into cubes because of longitudinal and transverse cracks (tending to crack across the grain). Infected wood may be greatly weakened, even before external evidence of decay can be seen. Brown rot is generally more serious than white rot. Old infestations of brown rot which have dried out will turn to powder when crushed. They are often labeled as “dry rot”. This common term is deceiving, because dry wood will not rot. Actually, wood kept dry will never decay.
Thus, one reason to have a periodic roof cleaning and a treatment with a Borate solution to preserve the wood.
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Cedar Shake Shingles – Common Problems
- Rot might be found in this material – especially if it is exposed to prolonged periods or moisture
- Cupping can occur – where both sides of the material lift
- Cracking or splitting is a defect that can create openings in unwanted locations
- Curling – where the bottom of the shake lifts up
- Burn-through is most often found near the center of the exposed area of the shake and can expose the felt underlayment to harmful ultraviolet rays – this can accelerate deterioration and can eliminate your second line of defense against roof leaks
- Exposed felt underlayment is an area of concern and might indicate improper installation of the roof
- Missing or damaged hip or ridge shakes are commonly found defects and will leave those areas open to the weather
- Exposed fasteners found anywhere in the roof surface are leaving unprotected openings in the roof and indicate improper installation practices
We suggest an absolute minimum amount of foot traffic, only when absolutely necessary and only by people knowledgeable about how to walk on these types of roofs.
Got Moss on your Roof? Removing Moss from Roof Helps Prolong the Life of your Roof!
Heavy moss can cause water to back up on the roof enough to flow over the top of the shakes. I have seen water do some very strange things to cedar shake roofs. The moss buildup should always be removed. Moss retains soil and moisture that can harm wood over time. Watch this video to learn more.
Having your roof professionally cleaned not only improves the appearance of your home, buy may prolong the life of your roof by years. Contact us today for a free estimate!
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