Redwood decking meets wildland fire standards

By Charles J. Jourdain President, California Redwood Association

THE superior performance of redI. wood lumber under fire exposure has been known for decades. Recent testing by numerous laboratories, in response to new standards for decks in California's wildland-urban inter- face, has reaffirmed redwood's reputation as a fire-safe decking product.

On September 21, 2005, the California Building Standards Commission unanimously approved the State Fire Marshal's "Wildland-

Keep the Gode

Newly adopted fire regulations in California will impact the use of wood products used in exteriors, and a new Tech Note from Western Wood Products Association can help identify what lumber products can be used for siding, decking and soffits.

WWPA's new Tech Note,"California Fire Standards & Exterior Wood Products," provides an overview of building standards that went into effect Jan. I for new construction in state Wildland-Urban Interface areas. The new product requirements, initiated by the State Fire Marshal's Office, are now in

A number of wood products organizations, including WWPA, have worked with state officials in reviewing available fire test data to meet the new regulations and defining preliminary product acceptance. A number of wood product fire tests have been successfully completed by companies producing products for the California market.

The Office of the State Fire Marshal of California also has granted approval for some wood products and species.

The Tech Nore lists the products that are covered by the generic approval and those that have successfully passed fire tests. It also shows required installation methods and specifications for siding, decking and soffits.

Some siding patterns in redwood, western cedars, and pon-

7A of the California Building Code. Also meeting the new rules is 2" and thicker decking in western cedars and redwood as well as one pattern in ponderosa pine for soffits.

Download the Tech Note from www.wwpa.org.

Urban Interface Fire Areas Building Standards." The new Chapter 7A of the California Building Code went into effect January 1,2008, for State Responsibility Areas and become effective July I ,2008, for Local Responsibility Areas.

The development of these standards was the culmination of two years of effort by representatives of building material manufacturers, home builders, fire-fighting agencies, and numerous other industry and state organizations in response to conflagrations such as the 2003 Cedar Fire in San Diego County. Development of testing protocols referenced in the new standard originated with a FEMA grant to the University of California Forest Products Laboratory after the Tunnel Fire in 1991. The newly adopted standard allows Construction Common or better grades of redwood decking to be used without restriction throughout California's fire-prone wildlands.

Section 704A.4.1

Decking of the new code states that if a decking material has a net peak heat release rate of 25 kWsq. ft. or less when tested in accordance with SFM Standard l2-l A-4 "Deck Test Standard" (Part A) and conforms to ASTM E-84 Class B flame spread it can be used in alf fire hazard severity zones without restriction. Construction Common or better grades of redwood meet both of these criteria without the need for fire retardant treatment. Decking materials not meeting both of these criteria will not be allowed unless the exterior wall covering to which the deck is attached is constructed of non-combustible or ignition resistant material.

Non-combustible decking (masonry and steel) or ignition resistant decking (fire retardant treated wood) are other optrons.

Tests on redwood decking conducted by the University of California Forest Products Laboratory, in addition to the more recent California Redwood Association-sponsored tests conducted by Underwriters Laboratories, Inc. and the Western Fire Center, indicate that the net peak heat release rate for redwood is in the 12l5 kWsq. ft. range. Both heartwoodand sapwood-containing grades of redwood successfully passed the modified Part B of SFM-4 using a class "B" burning brand as requested by the County of San Diego.

Previous tests on l-inch nominal thickness redwood heartwood resulted in the current Class B flame-spread rating. New tests conducted by the Southwest Research Institute Department of Fire Technology, verified the Class B flame-spread rating for 2-inch nominal Construction Common and Construction Heart grades of redwood decking.

Redwood's remarkable properties combined with coordinated, up-todate material performance testing has resulted in suppliers, builders, homeowners, and fire and building officials being assured that redwood decking can be used safely tion throushout all and without restricareas of California.