Cedar Shake Roof Services

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A Gorgeous Cedar Shake Roof on a gated estate in Stanwood, WA completed by Peak of Perfection.

Cedar Shake roofs are special. Nothing is quite like Cedar for longevity, appearance and R-Value. Cedar is gorgeous and is a renewable resource that is locally sourced. However, it is sad to say that far too many cedar shake roofs are replaced prematurely because owners are simply unaware of the need to regularly service and maintain them. Far too many cedar shake roofs are torn off when instead they could be restored and brought back to serviceable condition, often at a fraction of the cost.  


Cedar Roof Restoration

Don’t Replace your Cedar Shake Roof…Restore it! Cedar Shake roofs are modular and cedar is a surprisingly tough material. This means nearly any component of the roof can be removed and replaced. And while it is true that at some point you roof may not be salvageable, it is often just as true that often what a cedar shake roof needs is some repairs and a proper cleaning and restoration to last decades longer. It would be fair to say that if maintained regularly, a cedar shake roof could last as long as the building is standing. Our team of experienced cedar professionals will evaluate your roof, determine which components require replacement or restoration and give you a quote. Roofs which looked like they were done for can be returned to fully serviceable condition.  

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This roof in Bellingham, WA was in dire need of restoration. It was literally infested with moss, mold, algae and mushrooms…yes mushrooms. Conventional wisdom would have been to replace it…even amongst our fellow roof cleaners. We are not Conventional. 

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This is the same roof after being restored. 


Regular cleaning if your cedar shake roof is vital to its longevity. Removal of the debris, wood rot fungi, moss and lichen is crucial to the lifespan of the roof. Typically this should be done every 5-7 years. However, far too often a cedar shake roof is neglected. Decades of debris, moss and fungi take their toll. If the shakes are not structurally damaged to the point of failure, they can often be refurbished. Refurbishment is a more intensive process than cleaning. It can involve various methods of restoring the surface of the wood using multiple different products, balanced to meet the needs of the roof material. This is followed by the application of an oil to re-hydrate the shakes and allow them to expand and contract with changes in temperature and humidity. Shakes which dry out too much are subject to cracking and splitting. Restoration, while more costly than a basic cleaning, is still far less expensive than replacement. It can help bring an aged and unmaintained cedar shake roof back to life. Restoration can save you tens of thousands of dollars over the cost of replacement. A restored cedar shake roof also adds significantly to the value and marketability of a home. 


This roof is partially through the cleaning process. Notice the black wood rot fungi on the top vs the lighter color on the bottom shakes. 

Maintenance and Debris Removal. 

Your Cedar roof, being a natural material, should be maintained. Like all woods, cedar is subject to brown and black wood rot molds and will deteriorate if excessive moisture is allowed to remain in contact. Excess needles, dirt and debris will tend to build up in the spaces between the shakes and shoudl be removed annually. If not removed, the water this debris contains will allow fungi to start to colonize the roof and begin to break down the structure of the wood. It is this process which turns your cedar roof black. The organic layer this creates encourages other organisms such as moss, lichen and algae to colonize the shakes, degrading them further. These organisms further act to keep your roof wet and this is what destroys the integrity. If your roof is a light tone cedar color or a distinguished silver color, it is fine. But if it shows brown or black or has moss or lichens on it, it is in need of cleaning and maintenance  Proper maintenance must include removal of these organisms from the wood. Debris should be removed from the roof annually at a minimum. When debris is allowed to remain on the roof, it holds moisture that allows fungi to colonize. This includes all the tree debris which builds up between the shakes. 


If your cedar shake roof has moss, it is need of a proper, professional cleaning. Unfortunately, all too many times people or inexperienced contractors unknowingly put Moss Out, or Zinc Sulphate or Zinc Chloride powders on their roof to kill the moss. This is NOT recommended…particularly on a wood shake roof. Application of the zinc *will* kill the moss, but it also tends to have a drying effect on the shakes. In addition, the typical methodology and conventional thinking is that the zinc powder kills the moss and then it will simply rinse off. Unfortunately, this is not what happens in the real world. In the real world, a layer of dead material stays on the roof and falls into the cracks and crevices. This organic material then decays, creates a sticky organic layer which then becomes a great attractant and food source for more moss, algae, lichen and most importantly…wood rot fungi (aka mold). If they shakes are already infested with rot fungi, they tend to be more porous and easily allow the roots of mosses and molds to more easily infest the interior structure. The result is accelerated deterioration of the roof. While the moss may be gone, it is often back the next season with a vengeance.  It is for this reason, these products are highly discouraged. Instead, a cleaning which kills and removes the dead organic debris is called for along with a restoration of the surface so it can more easily resist further infestations.  

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You can see the gaps here beween the shakes. It is this area that can become thin and blow out if excessive pressure is applied to the roof. 

Pressure Washing?

We see a lot of contractors bid to pressure wash cedar roofs. This can be a serious problem. Not all cedar roofs are created or installed equally. A cedar shake is tapered at the top end. Because of the spacing, this leaves a single layer in the valley between the shakes, known as the drip edge. If the shake is thin, soft or worn, or has an incorrect amount of reveal, this leaves a very thin area. Pressure washing can blow this area out. It is for this reason we do not use high pressure on roofs. A very low amount of pressure is fine and a roof in serviceable condition will withstand this pressure, but a roof with a thin or soft drip edge will blow out, exposing the felt below and leading to leaks. 

Finishes. Sealants, Stains, Oils. 

One of the most frequent questions we are asked is what should be put onto the roof in order to maintain it? Our answer is simple…Oil. Cedar is a naturally oily wood and the only thing we recommend on that wood to replace the oils lost during evaporation and the improper use of zinc sulphate is more oil. 

The other frequent question is…should it be sealed? The answer to this is generally NO. The majority of cedar shake roofs are installed using more modern installation methods. As such, there is limited facility for the shakes to dry out from the underside. They depend on evaporation to achieve this. A sealant will trap moisture underneath the shakes leading to rapid colonization of wood destroying organisms and rotting from the underside. There has been more than one case of woods which looked serviceable on the outside, only to literally crumble under our feet…including one which was so bad a worker’s foot went all the way into the attic space. 

Stains. We will often recommend a light stain for your roof, particularly if new sections need to be installed. It MUST be remembered that a roof is a highly weathered surface and unless applied regularly, a stain will eventually weather off. Staining is also highly recommeneded if the home is to be marketed for sale.  

Safety. SAFETY. S A F E T Y!!!! 

There is simply no way to sugar coat this. Cedar Shake Roofs are extremely dangerous surfaces on which to work. They are slippery and there is always a chance that shakes can come loose under foot. It is for this reason that we will ONLY work on your cedar shake roof safely. No cedar shake roof will be cleaned without proper anchor points being installed. All operations are done with the greatest of care. We utilize PROPER Cedar Shake roofing shoe attachments called Korkers. We utilize proper fall protection equipment including the installation of permanent fall protecion anchors. Our employees are experts in proper roof and fall protection safety. If a roof cleaner proposes a cedar shake roof service and does NOT talk to you about proper safety equipment and permanent anchors points, walk away.  

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Glenn is harnessed up for safety and removing tree debris using compressed air on a cedar restoration project. 

The Process.

First, if there is a large amount of moss, we will likely do an initial application of a moss killing product to start an initial kill and start to dry out the surface. We will give this some time to work. Any loose, missing or broken shingles or top caps will then be replaced.  Then the process to fully clean and condition a cedar roof begins, starting with removal of any loose debris and dead moss which is brushed or blown off with high volume, low pressure water. The roof is then treated with our multi part cleaning solution formulated specifically for cedar which kills the fungi, mold and Lichen on the roof. We then rinse the roof and apply a neutralizing and brightening agent, followed by an oil/stain.