Weathering and aging of cedar shakes: what you need to know
Cedar shakes are renowned for their natural beauty and durability, making them a popular choice for roofing. However, like any natural material, cedar shakes are subject to the effects of weathering and aging. In this comprehensive guide, we will delve into what you need to know about how cedar shakes weather and age over time.
Understanding the beauty of weathered cedar
Natural patina
Cedar shakes develop a beautiful, silvery-gray patina as they age. This natural transformation enhances the aesthetics of your roof, giving it a timeless and rustic charm. In fact, most asphalt roofs take their names and color cues from natural cedar shakes. “Aged cedar” and “Dual gray” are the most common colors.
Enhanced texture
Weathered cedar shakes acquire a unique texture, with subtle variations that add character and depth to your roof. This aged wood texture is highly valued for its aesthetic appeal, and with regular maintenance to remove debris it offers longevity unmatched by synthetic materials.
Blend with the environment
As cedar shakes weather, they harmonize with the natural environment, becoming an integral part of the landscape. High-end custom home builders and architects prize the look of cedar to blend new construction seamlessly with the landscape and with established luxury neighborhoods.
Factors influencing weathering
Exposure to sunlight
The sun's ultraviolet (UV) rays play a significant role in the weathering process. Cedar shakes exposed to direct sunlight will weather more quickly. This UV exposure is expected, with cedar maintaining a long lifespan even in challenging climates.
Rainfall and moisture
Rainfall and moisture levels affect the rate of cedar aging. Shakes in dry weather may degrade more rapidly than those in rainier regions. Additionally, consider moisture and exposure to salt air when considering which fasteners to choose for your project. Correct installation is a key factor in longevity.
Air quality
Air quality, particularly in industrial areas, can impact how cedar shakes age. Pollutants in the air may accelerate or alter the aging process. Cedar can also be CCA treated prior to installation to prevent degradation caused by environment.
Effects of weathering on cedar shakes
Dimensional changes
Cedar shakes will naturally expand and contract with changes in humidity. Understanding this can help prevent potential issues, especially with installation. An experienced installer can help you understand cedar shake shrinkage and wood expansion. They should ensure the cedar is installed at the right exposure, based on the location of installation, pitch of a roof, and local building codes.
Cracking and splitting
As cedar shakes age, they may develop cracks and splits. These are typically aesthetic and don't necessarily compromise the roof's integrity. Choosing the right quality of cedar can prevent most of this.
Sometimes it is necessary to replace cedar shingles — and this isn’t always easy. If your building has decades-old cedar, finding a match with exactly the right size and milling technique can be tough. But we love a challenge. Contact us and we’ll help you source replacement shingles for any project. We even work with our mill partners to manufacture shakes and shingles that are no longer standard.
Moss and mildew growth
Weathered cedar shakes can provide a suitable environment for moss and mildew growth. This growth can decay the cedar more rapidly. Regular maintenance is essential to prevent this issue: particularly, blowing or sweeping debris off surfaces where it collects. We advise against power washing, which can damage shakes.
Resistance to insects and decay
Despite aging, cedar retains its natural resistance to insects and decay, which contributes to its longevity as a roofing material. Some property owners elect to also CCA treat their cedar wood before installation, which can further extend its lifespan.
Maintenance for weathered cedar shakes
Periodic cleaning
Regular cleaning is crucial to remove moss, mildew, and dirt, preserving the visual appeal of your weathered cedar roof. Using a low-pressure hose (not a high-pressure power wash) and a gentle detergent or low-concentration bleach solution is essential. We recommend cedar roof cleaning in the summer when it’s typically easiest to blow or brush off debris. Additionally, cedar can become very slippery when wet, so it can be a hazard to walk on a cedar roof in rainier months.
Sealing and coating
Sealing and coating can extend the lifespan of your weathered cedar shakes by providing additional protection against the elements. Old cedar shakes and shingles can be painted, and new cedar shingles can be stained or painted before or after installation. While there is no officially recommended product by the Cedar Shake & Shingle Bureau, some homeowners choose products such as cedar deck sealers to preserve the longevity of their roofs.
Rejuvenation options
Shake replacement
As cedar roofs age, inevitably some shakes will need to be replaced. This is a relatively simple process that a contractor can do. When cedar shakes age significantly and require extensive maintenance, you may consider shake replacement, in part or in whole, to preserve your roof.
Pressure washing
For cleaning aged cedar or cedar with a buildup of residue or moss, we do NOT recommend pressure washing, except by professionals and only on the lowest possible setting. While pressure washing can be an effective method to remove accumulated dirt, moss, and mildew from weathered cedar shakes, it can also dislodge shakes from their fasteners and quickly destroy the shakes or shingles on the roof. Instead, we recommend routinely using a broom or blower to remove debris during dry months.
Balancing weathered aesthetics and roof longevity
Regular inspections
Periodic inspections help identify issues early, allowing for timely maintenance and preventing potential problems. We recommend that homeowners inspect their own roofs at least once per year. Look for broken shakes or shingles, places where debris are pooling, any signs of metal bleeding from exposed fasteners, any sagging or discoloration in the roof, and any moss growth. If none of those signs are present, then we simply recommend maintenance at least once every five years to ensure that the roof stays in top shape.
Balancing act
There is a balance between preserving the weathered aesthetics of a cedar roof, and ensuring the functionality and longevity of your cedar shake roof. New shakes will look red in color, but within a few seasons will weather to a beautiful gray color. While it may seem unusual at first, most folks will actually admire the attention and care given to a roof by contributing to its maintenance, as opposed to completely re-roofing every 10-15 years, which is typical of an asphalt shingle.
How are your cedar shakes holding up?
Weathering and aging are natural processes that impart unique charm and character to cedar shake roofs. Understanding the factors influencing these changes and the effects of weathering, as well as implementing proper maintenance, can help you enjoy the enduring beauty and performance of your cedar shake roofing for years to come.
Cedar shakes are more than just a roofing material; they are a testament to the beauty of natural aging and a connection to the environment. Embracing the weathering process, with proper care and maintenance, ensures your cedar shake roof remains a striking and enduring feature of your home.