ACZA

Advantages of Chemonite® ACZA Pressure-Treated Wood

• Protects against fungal decay and insect attack, even Formosan termite. 

• Effectively penetrates coastal Douglas fir. 

• Long history of successful use. 

• Studies indicate resistance to carpenter ants, woodpecker damage, and fire. 

• Provides protection at all levels of exposure — above ground, ground contact, fresh water and salt water. 

• May be stored, handled, and worked like untreated wood. 

• Recognized by model building codes. 

• Leach resistant. 

• Can be painted or stained. 

• Leaves surface free of chemical deposits. 

Best Applications for Chemonite® ACZA Treated Lumber

Chemonite® wood is especially appropriate for industrial, utility, marine, and heavy construction applications, where coastal Douglas fir or other refractory species are used, or where longevity is a concern. Typical applications include: 

• Utility poles — distribution & transmission 

• Building poles 

• Foundation piling 

• Marine piling — fresh or salt water 

• Sawn timbers or supporting columns used for bridges, barns, homes, or other uses

• Agricultural posts 

• Post frame construction 

• Highway construction 

• Railroad crossties 

Safe Use and Handling Guidelines for Chemonite® Treated Wood

Construction: Bracing with round timber piles rather than sawn timbers is recommended for marine construction below high tide. All untreated wood exposed by cutting or drilling should be adequately field treated. Avoid removing the outer shell of wood where treatment is heaviest and decay-resistance greatest. It is recommended that all structures be prefabricated before treatment; minimize problems by specifying framing and boring before treatment whenever possible.

Worker Safety: Chemonite® wood 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 for ACZA Treated Wood

ACZA is listed in the American Wood Protection Association (AWPA) Standard P22 (formerly P5) for Waterborne Preservatives. Wood treated with this preservative is accepted in AWPA Standard U1 for applications in Use Categories 1 through 5, that is, from interior applications to saltwater immersion. Within the requirements of the standards, ACZA can be used to treat numerous species of wood, however its ability to penetrate makes it particularly useful in the treatment of coastal Douglas fir, for which it is most commonly used. 

AWPA standards are referenced in government specifications and model building codes for treated wood products. 

Chemonite® wood is also listed in standards of the Canadian Standards Association (CSA O80). 

Best Management Practices (BMP) for ACZA Pressure Treatment

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.

How Incising Improves Preservative Penetration in ACZA 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 ACZA Treated Lumber

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. One reason for substandard material can be use of a preservative other than ACZA that is not suited for refractory (i.e., difficult-to-treat) species. 

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. 

Recommended Fasteners and Connectors for ACZA Treated Wood

• Hot-dipped galvanized fasteners & connectors are recommended for use with Chemonite® ACZA-treated wood. 

• Some hardware manufacturers recommend only stainless steel connectors. We recommend no less than post Hot-Dipped Galvanized, HDG, fasteners (meeting ASTM A 153) and connectors (ASTM A 653 Class G185 sheet), where there is contact with ACZA-treated wood. In all cases, be sure to observe building code requirements. 

• In highly corrosive environments — such as exposure to salt air, industrial fumes, fertilizer storage, high humidity, and constant wetting — appropriate stainless steel should be used. For below grade Permanent Wood Foundations, building codes generally require stainless steel. 

• Always use the same type of metal for assembly of connectors and fasteners as dissimilar metals can accelerate corrosion. Aluminum or electroplated galvanized metals should never be used. These metals are not accepted by the building codes for use in exterior applications. 

Wood Species Best Suited for Chemonite® ACZA Treatment

For its dimensional stability, high strength-to-weight ratio, nail-holding capability, and other properties, Douglas fir is prized as a structural lumber. It is not easily treated by waterborne preservative systems, but the ammonia and heat used in the ACZA treating process enable Chemonite® preservative to provide effective protection of the wood. 

Douglas fir is not a true fir, but comprises several species in their own genus, Pseudotsuga. There are differences among these species and even within them. For some applications, AWPA standards distinguish between coastal Douglas fir (grown between the Pacific Ocean and the summit of the Cascade Mountains) and interior Douglas fir. 

ACZA treatment can also effectively protect other species, including red pine, eastern white pine, ponderosa pine, jack pine, spruce, western red cedar, northern white cedar, lodgepole pine, and even certain hardwood 

• Protects against fungal decay and insect attack, even Formosan termite. 

• Effectively penetrates coastal Douglas fir. 

• Long history of successful use. 

• Studies indicate resistance to carpenter ants, woodpecker damage, and fire. 

• Provides protection at all levels of exposure — above ground, ground contact, fresh water and salt water. 

• May be stored, handled, and worked like untreated wood. 

• Recognized by model building codes. 

• Leach resistant. 

• Can be painted or stained. 

• Leaves surface free of chemical deposits.