DCOI

Key Benefits of DCOI Treated Wood

• Effective against wood decay fungi and termites

• DCOI is not a Restricted Use Pesticide

• Not perisistent in soil and is stable and leach resistance

• Earned the EPA's President's Green Chemistry Challence Award in 1996 for its use as an alternative to trubutylitin (TBTO) compounds in marine andifoulant coatings.

• Used in water treatment, paints & coatings, adhesives, vinyl roof membraned, vinyl flooring, marine upholstery, outdoor furniture and shower curtains

• DCOI uses less energy, fossil fuel, and water to produce; with lower ecotoxiity than other materials used for ties.

Best Applications for DCOI

• Residential Decking

• Utility Poles

• Utility Cross Arms

• Rail Crossties/Sleepers

• Glulams

Safe Use & Handling 

DCOI treated wood products can be stored, handled and worked like untreated wood. As with any wood, wear gloves to avoid splinters, wear eye protection and a dust mask when sawing, drilling and sanding. Wash hands before eating or smoking. Dispose of cut ends in a proper landfill. Treated wood should not be burned in open fires or in stoves, fireplaces or residential boilers. Treated wood from commercial or industrial use may be burned only in commercial or industrial incinerators or boilers in accordance with state and federal regulations.

AWPA Standards & Building Code Requirements

The American Wood Protection Association (AWPA), a non-profit organization which promulgates voluntary wood preservation standards, developed a Use Category system that classifies treated wood based on its intended exposure and service conditions rather than by specific wood products. This system helps simplify selection for both professionals and consumers. Since most building codes now reference AWPA standards, the Use Category system is gradually replacing the older Commodity-based classifications in construction codes.

DCOI was first adopted in 2008 (formerly AWPA Std P8 No.6) and reaffirmed in 2000, 2006, 2014, and 2020.

Best Management Practices (BMPs) For Treated Wood Preservation

The Western Wood Preservers Institute, in conjunction with industry representatives, users, and scientists, developed BMPs to help ensure fixation of preservative chemical in treated wood prior to shipment. In the fixation process, some preservative components bond to the wood while others form insoluble precipitates. Specification of BMPs results in wood with a very high percentage of fixed preservative and may also reduce shipping weight. 

Why Incising Improves Preservative Penetration in Certain Species of Treated Wood 

In many western species, penetration improvement methods are employed to improve the depth and uniformity of preservative penetration into wood. Most commonly this is seen as a pattern of slits ("incisions") on the surface of lumber. Full-length incising and deep-incising are other methods, as are radial-drilling and through-boring, used mostly for poles and piling.

Although these methods can improve preservation, they can result in a strength reduction for the wood, depending on the pattern, size, and number of incisions. When treated sawn wood products have been incised, the reference design values must be multiplied by the incising factor, Ci, in accordance with section 4.3.8 of the National Design Specification for Wood Construction. A review of penetration improvement methods is recommended before insertion into a specification.

NOTE: Incising is required by the AWPA Standards for refractory species. DF is a refractory species with up to 75 % heartwood.

What "Treated to Refusal" Means for Wood Performance and Code Compliance

This phrase — Treated to Refusal — indicates that the wood was treated under specific conditions until it refused additional preservative, a point usually below the requirements of industry standards. The result is wood that cannot be relied upon to last as long as wood that meets standards. Such wood does not comply with model building code requirements for treated wood. 

To assure yourself of properly treated wood, look for the logo of an ALSC-accredited inspection agency on lumber tags or ink stamps. The logo often appears beside a Checkmark symbol.

Hardware Recommendations for Treated Wood Installations

DCOI is compatible with any hardware.

Suitable Wood Species for DCOI

• Mixed hardwoods

• Oak and hickory

• Coastal Douglas-fir, Western Hemlock and Western Larch

• Southern and Ponderosa pine