Building a Future for Distributors and Dealers of Building Products
January/February 2005 Volume 44, Issue 1
A Matter of Chemistry
Professionals have Mixed Reactions to Fastener Compatibility Issue
by Alan B. Goldberg
Mention fasteners for treated wood to contractors and wood preservative and fastener manufacturers and the response could be as varied as the recommendations for hardware.
“There is no (corrosion) issue,” some will say. “Just follow the recommendations.”
To others, there is a serious safety issue at hand.
As one fastener manufacturer put it quite simply, “copper and zinc just don’t like each other.” Unfortunately, that reaction has proven to be an expensive lesson in chemistry. With some fasteners, their combination with wood preservatives has been pretty corrosive. But other fasteners have not been affected.
A Brief History
What brought attention to fasteners and other hardware began with the Environmental Protection Agency’s (EPA) decision to ban the wood preservative chromated copper arsenate (CCA) for residential use, as of January 1, 2004 (see SHELTER magazine, July/August 2002). But two of the replacements—waterborne copper azole (CA-B) and alkaline copper and quaternary ammonium compounds (ACQ)—touted as more environmentally friendly products, presented another issue with their significantly high copper content (and high cost) ... a chemical reaction with unprotected metal.
“We haven’t seen or heard of any problems with fasteners although we know there are issues out there,” said Mike Reimer, president of Western Wood Preserving Co. of Sumner, Wash. “Our recommendations for fasteners have remained the same even though there have been changes in wood treatments. They are hot-dip galvanized or stainless steel.”
But one contractor, one of the largest deck builders in the country, sees it a little differently.
“The industry is facing a hard time as far as gaining confidence in today’s lumber,” said John Hart, structural design consultant for Archadeck.
He pointed out that ACQ, with its high copper content, reacts with galvanized and electroplated nails.
“As members of an association and ASTM, we have no means of testing ACQ. Even if it meets ASTM standards, that is no indication that it works. This is a minimum standard,” Hart said.
Hart added that some manufacturers have developed their own coatings with a guarantee that their hardware will last.
“As an industry, we don’t have the answers. But one of our objectives (as a charter member of the newly formed North American Deck and Rail Association) is to pressure the International Code Council (ICC) and ASTM to come up with a test for ACQ,” he explained.
The Need for a Standard Test
Hart said that other than builders getting together to form this organization, nothing is being done to test.
Concern about a standard test for ACQ is also shared by W.C. Litzinger, managing member of Universal Fastener Outsourcing LLC.
“There is no widely accepted test and no official approvals for ACQ-treated lumber. The current codes are for CCA lumber, which can no longer be used for residential applications. This situation is very unfair to the installer,” Litzinger said.
Litzinger mentioned that new test protocols have been developed and will be presented at the North American Deck and Rail Association meeting. He said the ICC also has some new protocols, but in its latest report, it did not address the ACQ issue.
“We feel very frustrated because no one (fastener and wood preservative manufacturers) wants to take this issue seriously, at least not until ICC publishes a new code. At this point, the industry seems to be content with ASTM A-153,” Litzinger added.
Universal offers an alloyed, electroplated coating for nails, screws and connectors that has been tested extensively and is recommended for ACQ.
The Issue Expands
At Osmose Inc., recommendations for fasteners have never changed, even with CCA lumber, according to Al Haberer, manager of communications.
“Although treated wood seems to be at the center of the issue, the real focus is the quality of the fastener. We recommend true hot dip on hardware, connectors or metal products that are used with treated wood.”
Haberer pointed out that it is important to use the fasteners and hardware recommended by their manufacturers for use with the new preservatives. He said there are two ASTM standards that apply—A-153 for fasteners and A-653 for connectors and sheet products.
Haberer says he recommends those manufacturers whose products have been tested in accordance with these standards.
Haberer mentioned that the fastener issue is not new. It only got bigger.
“For as long as I can remember, the quality of the fasteners has been an issue. In the interest of saving money, some have used poor-quality fasteners and they did not last. What has changed is that the newer treated woods are more corrosive, and, therefore, less forgiving. What magnifies the problem is the sheer number (thousands) of metal products that go on treated wood. If they have been electroplated, they may fail.”
Haberer said that some associations recommend stainless steel for all applications.
“You can never go wrong with stainless steel. But it is the most expensive material, and we believe there are many applications where the use of stainless steel is an unnecessary cost.”
In anticipation of EPA’s ban on CCA, Simpson Strong-Tie developed products for the new wood preservatives. According to Richard Chapman, national advertising manager, the company has performed more than 1,800 tests on treated wood to determine corrosion resistance.
“We came out with a triple zinc-coated product which we believe is especially effective in areas where corrosion is prevalent,” said Chapman . “We also have a product that is used as an excellent barrier between the connector and the wood because it isolates the steel surface from the wood so there is no galvanic action.”
Working with Chemical Companies
To one fastener manufacturer, the key to resolving the issue is by working closely with chemical companies.
“Lets face it. Copper and zinc just don’t get along,” said Tim Gillis, marketing manager for FastenMasters. “When they come into contact, especially with water involved, there will be corrosion. So the main key is to use a high-quality epoxy to act as a barrier between the increased levels of copper in the wood and the zinc plating with the screw, which is what we have done. We worked directly with three main chemical companies to test our product. Our new fastener has been developed for ACQ and CA-B decking. The guarantee is right on our website.”
For the Southern Forest Products Association, creating an awareness of the problem and educating its audience has been a top priority.
“We’ve been communicating closely with the design and construction community for the past eighteen months,” said Richard Kleiner, director of treated markets. “Looking at this situation from the supply side, the transition from CCA to other wood preservatives has been a very smooth one.”
Kleiner believes that users have always known about the fastener issue. He said building codes have always required hot-dip galvanized or stainless steel.
“Our position is that either of these two options is acceptable, but hot dip is the minimum requirement. CCA wasn’t as corrosive so users didn’t pay as much attention to fasteners as they probably should have,” Kleiner said. “If there was a problem, it usually had to do with appearance. Today, with the higher corrosivity of the new treatments, the problems could be structural.”
“As far as we are concerned, this (corrosion) issue is as important as the issue of mold and moisture control,” he added.
Kleiner pointed out that 43 percent of southern pine is treated and “we have a responsibility to educate our audience (designers, engineers, builders and code officials) on the problem with the new preservatives.”
The association has been giving extensive presentations on this topic at industry trade shows.
The Flip Side
Not everyone agrees that there is a serious problem.
“I think this is overblown,” said Huck DeVenzio, manager of marketing communications for Arch Wood Protection. “If recommendations are followed, there should be no problem.”
DeVenzio explained that most builders now realize that the new recommended hardware adds to the cost, but at the same time, making the change allows them to build with confidence.
“Taking a shortcut to save money creates a problem,” he said. “Whenever there is a new development, there is going to be some kind of change. With the phase-out of CCA-treated lumber (for residential use), industry recommendations have changed and the use of the traditional hot-dip galvanized hardware is no longer acceptable. CCA-treated wood often allowed you to get away with using lower levels of galvanized hardware. With the greater amount of copper in the next-generation treatments, that is an invitation to failure.”
Arch Wood recommends galvanization that meets specific standards and is very actively publicizing its recommendations.
“We’re saying that you don’t have to use stainless steel,” DeVenzio said.
He added that ceramic-coated hardware is also acceptable where the manufacturer agrees.
There are a few points everyone can agree on. Stainless steel is the best, although not the most economical, choice for fasteners and other hardware. The higher copper content of the new wood preservatives requires fasteners and other hardware with a more effective protective coating to prevent rust, and the fasteners and hardware of yesteryear—except stainless steel—will not cut it.
There is plenty of room for disagreement, however. Some say there is no fastener/hardware problem if the user simply follows the manufacturer’s recommendations. Others will say there is a significant problem because there is no ASTM or standard test for testing fasteners and hardware with the new wood preservatives and that the industry is content to use an ASTM that does not apply. In addition, with the dozens of fasteners on the market that are not adequately coated, decks are going to fail structurally because contractors may not want to spend the additional money for the necessary products.
Although the reaction to the new wood preservatives has been mixed, manufacturers, contractors and associations are working together to achieve better compatibility between treated wood and corrosion-resistant hardware. It’s all a matter of chemistry.
Alan B. Goldberg is a contributing writer for SHELTER.
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