Why do Cedar Shake Roofs and Siding Need Cleaning? 

Cedar and redwood shake roofs and siding, when properly maintained, have an expected material lifespan of 40 to 60 years. Without proper maintenance, however, they tend to only make it about 20 years on average. Most homeowners are never told that they need to keep their cedar shakes clean in order for their roof to last.

On their own, cedar and redwood shakes do not decay. The decay comes as a result of moisture. Modern cedar shakes are laid on top of roof felt, a type of underlining that is great at preventing water into the home, but that causes the shakes to retain moisture. Cedar is very soft and porous, and when it rains, the shakes collect the moisture and swell, which causes them to retain water. Trapped moisture leads to organic growth, such as algae, moss, lichen, fungi, or mold. This allows for the organic growth above to damage the shingles. If left on the shingles, those growths eat away at the shingles, exposing the felt beneath, and destroying the water barrier. Cleaning these from the shakes is critically important to extend the life of the cedar shake roof.

It typically takes about 10 years of not cleaning the shakes for a homeowner to start noticing the growth of moss, mold, lichen, and graying discoloration on their shingles. Most do not realize that they should have had those shakes cleaned all along. Even after years of neglect, a good cleaning followed by regular maintenance (typically every five years or so) will solve the problem and help extend the life of the roof.

If you find areas where shakes are damaged or missing, you should recommend replacing those. UV light can damage the roof’s underlining if the shingle is not there to protect it. Also, trees should be cut back to where they do not hang over the roof and cause additional moisture damage. You’ll want to inspect the roof for shakes that are missing or damaged before giving an estimate, then include their replacement in your costs. Repairs are often a service that is offered when restoring cedar shakes. There will be some that are missing, some cracked and split, some rotted, and all need to be replaced. This can easily be accomplished with a battery-operated nail gun and new cedar shakes.

How to Clean Cedar Shake Roofs and Siding

Cedar shakes are typically cleaned the same way you’d clean other exterior wood surfaces, using the same products. Sodium hypochlorite (bleach) is typically not a good option for cedar shakes. Because cedar shakes are so porous, and because bleach goes to work on the first thing it hits, sodium hypochlorite often does not reach the organic growth’s roots that are embedded below the surface. Using sodium hypochlorite will also leave the shakes looking bleached out. (You can read more about why bleach does not work well on wood here.) 

Our recommendation is to soft wash the cedar shakes, using a system such as the ProTool Clever and the Deck Restoration Plus line of professional wood restoration products

What are the Best Products for Cleaning and Restoring Cedar Shakes? 

Everett Abrams, “The Wizard of Wood,” is the owner and founder of Deck Restoration Plus (DR) products recommends a two-step cleaning process that starts with using an alkaline-based product, such as DRP's Cleaner or Restorer, followed by a brightener.

Deck Restoration Plus (DRP) Cleaner

Designed and used by the "Wizard of Wood" himself, Deck Restoration Plus Cleaner is designed to clean and prep new or grayed wood, removing mold and mildew to help restore the wood back to its natural color. 

• Unique, professional formula  
• Safe and effective on all exterior wood decks, siding, lattice, fencing, and all other natural wood structures. 
• Safe for us on composite decking. 
• Environmentally friendly
• 100% biodegradable
•  Does not contain any chlorine compounds or hypochlorite bleach

Deck Restoration Plus Cleaner & Remover 

This formula is designed for those more challenging wood surfaces. DRP's Cleaner and Remover makes cleaning and removing coatings a one-step process. 

• Provides superior cleaning 
• Removes many coatings (weathered and transparent)
• Safe and effective on all exterior wood decks, siding, lattice, fencing, and all other natural wood structures. 
• Safe on composite decking. 
• Environmentally safe 
• 100% biodegradable.

Deck Restoration Plus: Deck & Wood Restorer

This amazing product removes organic growth as well as restore the wood all in one step. 

• Concentrated sodium metasilicate-based cleaner
• Water-Based
• Safe for use on pressure-treated pine, oak, cedar, redwood, and other common wood surfaces
• Restores weathered wood to its natural color
• Removes stains caused by mold, mildew, and mosss.
• Contains no sodium hypochlorite (bleach)
• Undiluted gallon covers approximately 100-150 Square Feet. 
• Overall coverage varies depending on dilution rate and substrate 
• Concentrate makes up to 20 gallons

Why You Should Use a Wood Brightener after You Clean the Cedar Shakes

Wood brighteners serve 4 purposes: 

1. Wood brighteners neutralize the surfaces. The detergents used to clean wood are high alkaline, leaving the wood's pH out of balance. 

2. Wood brighteners neutralize and remove iron and metal stains in the wood. 

3. The acid in the wood brightener opens up the wood's pores, which allows the coating to adhere better.

4. Wood brighteners lighten and brighten the wood, making it more aesthetically pleasing. 

After you clean the wood, we recommend going back and applying a brightener, such as DRP’s  Wood and Deck Brightener, which uses oxalic acid along with a proprietary blend of other materials. Oxalic acid is sometimes referred to as “wood bleach” because of how it reacts with the tannins in the wood, really bringing out the natural color. DRP’s Deck Brightener will also remove metal stains, such as nail bleeds. If left untreated, these are really noticeable, especially when you apply a stain.

DRP Wood and Deck Brightener

Apply DRP's Wood and Deck Brightener to wet wood surfaces and you'll see the color come back before your eyes to like-new condition!

• Unique professional formula
• Safe and effective on all exterior wood decks, siding, lattice, fencing, furniture, and other wooden structures
• Safe for use on composite decking
• Environmentally safe
• 100% biodegradable

And undiluted gallon covers approximately 200-250 square feet. Overall coverage varies depending on dilution rate and substrate concentrate makes up to 20 gallons.

**NOTE** Since there is a wide variation in the quality and variety of wood surfaces, test on an inconspicuous area and allow to dry before general use

Should I Seal Cedar Shakes?

Your customer will ask this question, and the answer is “it depends.” Because of sun exposure, the coating on a cedar-shake roof will not last a long period of time -- less than the 2  years that it lasts on the horizontal surfaces on decks. The customer concerned more with appearance should have this explained in detail. If your customer wants you to periodically return for maintenance in order to extend their roof's life, then yes, you should seal shakes. Otherwise, they may be disappointed by how quickly the sealer fades. 

Deck Restoration Plus Stains

• Easy-to-apply and maintain products enhance the natural grain and characteristics of the wood.
• Penetrating water-based stain, not a film-forming water based stain, so it soaks into the wood rather than just sitting on th surface.
• Can be applied to wet or dry wood, which helps prevent wait times when scheduling
• Does not attract mold or mildew growth like oil-based stains
• Doesn't blister or peel
  
• Allows the wood grain to show through
• Available in a variety of colors
• Lasts approximately 2 years on horizontal surfaces and 4 years on verticals.
• Available in one or five-gallon options
• VOC Compliant 
• Environmentally Friendly 
• UV Resistant
• Superior Water Beading 
• Easy Future Maintenance 

Example of one of six color options for DRP wood stains. Available in single gallon or five gallon options. 

Learn Wood Restoration from the "Wizard" himself! 

You can learn more about cedar shake restoration, along with all things wood, from the "Wizard of Wood" himself in the Deck Restoration Plus (DRP) Exterior Wood Restoration Manual, written by Everett Abrams. 

Contents include: