Under pressure: new chemical alternatives for pressure treated lumber have framing fastener and hardware manufacturers jumping through hoops - News

Tools of the Trade, Sept-Oct, 2003 by Katy Tomasulo

On January 1, the lumber industry will undergo a major change as the EPA-phased transition away from CCA--the chemical used most commonly for pressure treated lumber--begins. CCA-treated lumber is being phased out for most residential uses after a voluntary agreement between the EPA and the lumber industry.

In its place, alternatives are being transitioned into the market. ACQ and Copper Azole are the most common for replacing CCA in traditional uses like decks and sill plates. The three leading treated lumber suppliers are Osmose, which produces ACQ-based Nature Wood, Chemical Specialties, maker of ACQ-based Preserve, and Arch Wood Protection, which makes Copper Azole-based Natural Select.

These manufacturers, as well as the Southern Pine Council, are recommending hot-dipped galvanized or stainless steel fasteners for use with the new lumber. But for those in the fastener industry, it may not be that simple. There is a concern among some that the new chemicals are more corrosive than CCA, and therefore many fastener manufacturers aren't ready to say that all hot-dipped galvanized nails and screws are adequate. In addition, "hot-dipped galvanized" can mean different things between brands. These recommendations also limit other types of coatings that also may be effective because there is no agreed-upon protocol with which to judge them.

In these early stages, fastener manufacturers are taking different approaches. In keeping with the recommendations of the treated lumber manufacturers, Maze Nails is recommending its Stormguard double-hot-dipped galvanized fasteners. Others are testing their products in the new material, some using ASTM tests already in use. Senco is currently testing its products, and in the meantime is suggesting that customers use stainless steel fasteners to be safe, not only for structural reasons, but also over concerns that regular fasteners may generate red or white rust in reaction to the chemicals. Quik-Drive says early testing results on its N2000 mechanical-galvanized product look promising for use in ACQ lumber. Stanley-Bostitch currently recommends its stainless steel or hot-dipped galvanized nails that meet the ASTM A153 standard for hot-dipped. Paslode is recommending its hot-dipped galvanized fasteners or its TLN nails, which have a urethane overcoat for additional protection. For connectors, Simpson Strong-Tie has performed extensive testing and for now is recommending a minimum of ZMAX G185 hot-dipped galvanized when the use of stainless steel connectors is not possible. It also reminds users not to mix hot-dipped galvanized and stainless steel fasteners and connectors. USP Structural Connectors also has done corrosion testing and is recommending using a minimum of its Triple Zinc G185 connectors.

Plating Technology developed and recommends the PT2000 (pictured), a line of nails and screws with an alloyed electro-plated coating that they say will go more than 1,000 hours in the company's ASTM B117 tests with no red rust. PrimeSource has tested and approved its PrimeGuard Plus triple-polymer-coated fasteners, previously used in the auto industry, for use with ACQ.

The good news in this debate is that it is putting more focus on the need for industry-wide fastener testing protocols. The International Staple, Nail, and Tool Association (ISANTA), which already was in the beginning stages of creating testing protocols, is working even harder to develop standards that manufacturers can use not only to test their fasteners, but that also would make it easier for consumers to make purchasing decisions according to the work they're doing and the environment they're in.

The issue is changing everyday. In the meantime, the best bet is to contact your fastener, connector, and treated lumber manufacturers to find out which products have been tested and that they recommend for the new materials. While the transition is expected to go smoothly, builders should continue to pay attention to any new installation requirements.

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