A year ago, Pat Nicholson, owner of Deckmasters, a Pittsburgh-based deck building franchise with eight branches, called his treated wood supplier and the manufacturer of the fasteners his company uses into a meeting. There, the contractor dumped a bucket of rusted and corroded wood screws onto the table and demanded to know what the manufacturer intended to do about the problem of fastener degradation. When the assurances he was seeking were not forthcoming, Nicholson switched fastener suppliers. He's since changed fastener lines several more times.
Damage Report With treated lumber suppliers voluntarily phasing out CCA (chromated copper arsenate) as of the end of last year, the two non-arsenic based chemicals now widely used to treat deck planks and framing — copper azole and alkaline copper quaternary or ACQ — are reported by many contractors to rust and corrode fasteners, bolts, flashing, and joist hangers, causing widespread concern about liability issues down the road.
Makers of screws, nails, and other products used to join deck boards “got caught flat-footed, and now they have lumberyards yelling and screaming at them,” says a Pennsylvania-based treatment plant owner who requested anonymity. “It's left a few people with their asses on the line.”
Others describe the situation as having been brought about by a “wait and see” attitude right on down the supply chain.
Solutions Sought Manufacturers of steel screws have scrambled to find new ways to coat their products to effectively resist corrosion, an effect Mark Guthrie, technical manager for Massachusetts-based FastenMaster, attributes to the high copper content of both compounds. Guthrie says the copper interacts with moisture, oxygen, and the zinc traditionally used to treat screws, creating a corrosive effect. Demand for a product that will resist corrosion has “kept the phones ringing” at FastenMaster, which makes a copper-treated steel screw called Guard Dog.
Other attempts to make screws corrosion-resistant similarly involve creating new types of finishes. Two years ago, for instance, Titan Metal Works, in Wheeling, Ill., introduced a product called SplitStop, with a triple zinc overlay covered by a copolymer coating. Sales manager Mike Tipps says the product comes with a lifetime warranty against corrosion and costs half of what the company's stainless steel nails cost. (Stainless steel nails can stand up to the corrosion problems.)
Contributing to the problem is the fact that the fastener industry, which has standards for salt and acid exposure based on extensive testing, has no such standard for steel screws used in ACQ- or copper azole-treated wood.
Nonetheless, many manufacturers have invested in research and development in an effort to create screw finishes resistant to the rusting effects of the new compounds. Products recommended (by the manufacturers that produce them) for use with ACQ are listed at www.treatedwood.com.
Nicholson, who's been using ACQ-treated boards for nearly two years, says he's not taking any chances. Stainless steel screws, which double his fastener costs per job — from about $150 to $300 — are now standard at the company.