Cedar’s Remarkable Moisture Resistance

Cedar Gazebo

Western Red Cedar and Northern White Cedar are coniferous members of the Cypress family Cupressaceae. However, many people know Western Red Cedar for its rustic, resilient furniture. Others may know cedar as the sauna wood which withstands a lot of sweat and heat. From the traditional cedar-lined chest to Native American customs and uses, a large cross-section of society finds value and joy from using cedar wood.


The Western Red Cedar tree, or Thuja plicata, primarily grows in the Pacific Northwest region of the US. The Northern White Cedar tree, or Thuja occidentalis, primarily grows in Eastern-Southeastern Canada and adjacent states of New England and the Great Lakes region west to Minnesota. Western Red Cedar is a large-to-very-large tree and can grow in some areas up to 230 ft. tall. It is also long-lived and some trees can live well over a thousand years, with the oldest verified being 1,460 years old. By contrast, Northern White cedar is a smaller tree and commonly grows up to 50 ft. tall, but a few trees can grow as large as 80 ft. It grows relatively slowly in swamp areas or on other saturated lowland sites and some trees can reach the ages of 400 years and greater in these habitats. One tree from Ontario was dated at more than 1,650 years old.


Cedar Fence

Western Red Cedar is one of the world’s most durable woods, as it has a natural resistance to moisture, decay and insect damage. It has twice the stability of most commonly available softwoods due to its low density and shrinkage factors. It produces long, lightweight lengths of timber with a fine straight grain and uniform texture. This makes it easy to cut, saw and nail with common tools. It also can be planed to a smooth surface or machined to any pattern. It can hold glue bonds and also provides a good base for many types of paints and stains since it lacks pitch and resin. It is also valued for its distinct aroma as its pungent aromatic oils are believed to discourage moth and carpet beetle larvae infestations. All of these factors make it the premier choice for either interior or exterior home use.

Northern White Cedar is the lightest of any commercial wood in the United States. It is even-grained and finely textured. The heartwood is resistant to decay and subterranean termites. It is easy to work, glues well and holds paint well. It also experiences little dimensional change, but it should be noted that the wood is soft and has low mechanical properties such as bending strength and nail-holding abilities. The wood has a characteristic pleasant aromatic odor of the “cedars”. A considerable amount of “cedar leaf oil” is used in cleansers, disinfectants, and insecticides, to name a few uses. The wood has been primarily used to make rustic fencing and posts, but can also be used for cabin logs, lumber, poles, shingles and other specialty type products.

Cedar is a natural wood for longevity and an excellent wood choice for various applications.  The oils produced by the wood species also give cedar its distinctive and pleasant aroma. Cedar’s natural resistance to moisture, decay and insect infestation makes it much more resilient in outdoor applications. Properly finished, cedar will last for decades even in harsh environments.


MMC220 Moisture Meter

Cedar’s natural longevity can be enhanced by basic moisture content (MC) measurement and management. All wood species, even cedar, are subject to natural processes. MC resides in the walls and in the nuclei of all wood cells. Once a tree is cut and kiln-dried, its MC still fluctuates according to changes in the relative humidity (RH) and temperature of its surrounding environment. This is especially pertinent to cedar users because so many use the wood outdoors.

MC is measured by a wood moisture meter. The simple use of a damage-free or pinless moisture meter means users can quickly run a wood moisture meter along the entire wood surface to read MC levels expressed by a percentage: the amount of moisture in the wood. These days, technology allows users to easily program in each wood species so that the wood moisture meter produces an MC% reading which takes specific properties into account. In other words, today’s wood moisture meter reflects the true state of the cedar’s actual MC. By checking the MC of cedar during construction or installation, its natural durability and longevity can be carried to its full extent.

Wagner Meters produces several moisture meters for wood, depending on the application. The MMC220 Extended Range Wood Moisture Meter is the most popular model from Wagner Meters because it measures the MC in common softwoods (such as cedar), hardwoods and also exotic wood species. Furniture makers may use the Wagner Meters MMC210 Digital Proline Moisture Meter to discover if the cedar’s MC is good to go prior to construction of a cedar chest. Even do-it-yourself wood flooring restorers could utilize the Wagner Meters L607 Waterborne Finish Moisture Meter (discontinued) to determine when the wood flooring surface can take the next coat of eco-friendly wood finish. All hand-held wood moisture meter products from Wagner Meters measure the MC up to a ¾” depth penetration below the wood surface.

Do your part to protect the legacy of cedar. Measure its MC before leaving it to the elements.

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Troy Edwards

Troy Edwards is Technical Service Supervisor for Wagner Meters, Inc., where he oversees manufacturing, quality control and IT service for their electronic measurement products for the building and construction industry. Troy holds an AAS in Electronics Technology and has over 20 years’ experience in various electronic manufacturing and production positions.


  1. […] oil in it also helps the threads resist water damage which is absolutely invaluable to those who are going to be using this as outside furniture as […]

  2. Michael says:


    My name is Michael and I am the sustainability coordinator for the University of Washington. We are currently building a computer operated solar kiln and we have some questions. We would like to set it to a standard temperature and humidity and were wondering if you had any recommendations?



    • Ron Smith says:

      Hi Michael,

      I suggest that you contact the Oregon State University Forest Products Department if your own Forest Products department cannot provide some guidance.



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