Forest Products Laboratory -- Forest Service -- USDA

You are receiving this message since your browser does not support JavaScript or you have JavaScripts disabled in your browser.The US Forest Service is conducting a Web survey, delivered via Javascript, to better understand our Web site visitors, what sorts of information they are seeking, and to see how well we are currently satisfying their needs. If you are interested in further information, please contact the Webmaster at: webmaster@fs.fed.us.




	WELCOME:
	About Us
	Search FPL Resources
	Press Room
	FAQs
	Partnership Opportunities
	Research Programs
	Publications
	Painting & Finishing
	Announcements
	Other Resources
	Advanced Housing Research Center
	Coalition for Advanced Wood Structures
	Wood Transportation Structures
	Wood Anatomy & Identification
	State & Private Forestry Technology Marketing Unit
	FPL Employees Area


	Forest Products Laboratory One Gifford Pinchot Drive Madison, Wisconsin 53726 (608) 231-9200 Contact Us...

You are here: home > rwu > preservation > durable

Frequently Asked Questions about Wood Preservation

More Information

Click for more information on the topics below:

	Topical Publication Lists
	o	Acid copper chromate (ACC)
	o	Alkaline copper quat (ACQ)
	o	Ammoniacal copper citrate (CC)
	o	Copper azole (CBA-A or CA-B)
	o	Copper dimethyldithiocarbamate (CDDC)
	o	Environmental impacts of treated wood and methods to reduce the impacts
	o	Disposal and reuse of treated wood
	o	Natural durability
	o	Control of moisture in buildings
	o	Experimental preservative treatments
	o	Research methodologies in the field of wood preservation
	o	Effect of preservative treatment on mechanical properties
	o	Wood products production and consumption
	o	Field treatment

	Links to other sources
	o	American Wood-Preservers' Association (http://www.awpa.com/)
	o	Forintek Canada Corp./ Canadian Wood Council (http://www.durable- wood.com
	o	Southern Pine Council (http://www.southern pine.com/)
	o	Western Wood Preservers Institute (http://www.wwp institute.org/)
	o	U.S. Environmental Protection Agency (http://www.epa.gov/)
	o	US Forest Service, Forest Products Laboratory (http://www.fpl.fs.fed.us/)

	FPL Publications
	Recent FPL Publications are generally availabe from our Web site at http://www.fpl.fs.fed.us/ publications.html as PDF files. The most recent FPL publications are listed in "Dividends from Wood Research," FPL's semiannual listing of new publications. Sections of the listing relevant to wood preservation are "Durability" and "Decay Processes and Bioprocessing."
	o	Most recent issue
	o	Cumulative list (January 1996 to present)
	Two chapters of the Wood Handbook are particularly relevant:
	o	Wood Preservation, Chapter 14
	o	Biodeterioration of Wood, Chapter 13
Send comments to: Carol Clausen, Project Leader Wood Preservation US Forest Service, Forest Products Laboratory One Gifford Pinchot Drive Madison, WI 53726-2398 cclausen@fs.fed.us top of page

Q: What about naturally durable species?

The heartwood of some wood species contains chemical extractives that prevent attack by decay and insects. The extent of natural durability depends on the wood species and also varies within the same species and even the same tree.

Commercially available naturally durable species such as redwood and cedar are not as consistently durable as wood that has been pressure treated with standardized preservatives. However, these species do usually perform well in above-ground applications (for example, decking). Some hardwood species, such as osage orange or black locust, appear to be very durable but are not commercially available in suitable volume or dimensions. Some tropical species are also very durable, but use is limited by cost, availability, and issues with verification of the wood species. Some individuals can have adverse reactions to natural chemicals found in some wood species.

Broad groupings of the natural decay resistance of the heartwood for several domestic species are listed below. For almost all species, the sapwood has low resistance to decay. As indicated below, the decay resistance of second-growth wood may be less than that traditionally associated with the old-growth wood. This listing and a similar grouping of imported species can be found in the Wood Handbook in Chapter 3.

For information on durability, preservation, and toxicity of individual species, one can search the on-line database of FPL's Center for Wood Anatomy.

FPL publications on natural durability of wood

Natural decay resistance of the heartwood for domestic species

Resistant or very resistant
Baldcypress (old growth)
Catalpa
Cedars
Cherry, black
Chestnut
Cypress, Arizona
Junipers
Locust, black*
Mesquite
Mulberry, red*
Oak (bur, chestnut, Gambel, Oregon white, post, white)
Osage orange*
Redwood (old growth)
Sassafras
Walnut, black
Yew, Pacific*
* These woods have exceptionally high decay resistance.

Moderately resistant
Baldcypress (young cypress)
Douglas-fir
Honeylocust
Larch, Western
Oak, swamp chestnut
Redwood (second growth)
Pine, eastern white
Southern Pine (longleaf, slash)
Tamarack

Slightly or nonresistant
Alder
Ashes
Aspens
Basswood
Beech
Birches
Buckeye
Cottonwood
Elms
Hackberry
Hemlocks
Hickories
Magnolia
Maples
Oak (red and black species)
Pines (other than longleaf, slash, and eastern white)
Poplars
Spruces
Sweetgum
True firs (western and eastern)
Willows
Yellow-poplar

Frequently Asked Questions

The first questions address new restrictions on the use of CCA-treated wood and the available alternatives. Then other frequently asked questions on wood preservation and related topics are also addressed. With few exceptions, references in this document were limited to publications of the Forest Products Laboratory. These answers are not intended to represent a complete review of the available literature.