Home | Previous | Table of Contents | Next
ALTERNATIVES TO PRESSURE TREATED WOOD
In an article titled Arsenic and Old Wood we learn some alarming facts from the very makers of CCA treated-wood. "Wood preservers could easily switch to arsenic-free formulas- using the same equipment and procedures-if consumers demanded it. "It's what I've been trying to argue for years," says Douglas Mancosh, president of BB&S Treated Lumber of New England, one of North-East's largest wood preservers.
As a hedge against any future federal and state bans on chromated copper arsenate, the three licensed suppliers of the preservative have developed a new generation of chemical mixes: ammoniacal copper quartenary (ACQ), copper azole and copper citrate. In addition, other companies have recipes to protect wood without arsenic or chromium. The most heavily promoted is Kodiak Preserved Wood, made with copper dimethyidithiocarbamate.
All of these alternatives are ready to go- the Environmental agency says they're safe, and the American wood Preservers Association says they work. However, the association's endorsement for copper azole is limited to above-ground use; ground contact approval is pending. The formula is common in Japan and Europe, in part because of concerns about the hazards of arsenic in traditional pressure-treated wood. The other three alternatives, ACQ, copper citrate and the The new formulas cost more because they are richer in expensive copper. But wood and labor, not chemicals, are the most costly elements of wood-preserving, Mancosh says; these remain constant no matter what chemicals are used. His company uses ACQ to treat a small portion of its wood, and he says the finished products cost 8 percent more than the standard pressure-treated wood. "It's pretty insignificant," he says.
In Chippewa Falls, Wisconsin, another wood preserver, Northern Crossarm Co., switched to ACQ last fall because of fears about worker safety and its own liability, owner Pat Bischel says the new wood generally costs about 5 percent more than the old.
Of the alternatives, ACQ is the least expensive and most common. Only one company California uses copper citrate to treat Douglas fir. Kodiak is the most expensive, but it includes a color stain that the other treated woods lack.
Mancosh, still churning out bundles of wood treated with a chemical recipe dating from the 1930's (CCA) says the industry could switch to the arsenic free alternatives tomorrow. But the industry is fragmented and hard to move, he says, "There's no one to take the lead. To me it seems an absolute no brainer to make the switch."
Despite all the concerns about pressure-treated wood, there might be some justification for using arsenic if chromated copper arsenate were the only formula available. But safer recipes exist, and some are just as effective.
The most common compound known as ACQ, manufactured by Chemical Specialties
Inc. of Charlotte, North Carolina. The company, which also makes about one third
of all CCA sold, has had little success selling the safer alternative, says
Tom Bailey, the company's marketing manager. Although wood with ACQ costs as
little as five percent more than the standard pressure-treated lumber, that
is a big enough premium to prevent most retailers from stocking it, Bailey says.
"Unfortunately the choice is not ours to make. The market is being driven
by retailers, and these retailers are under more pricing pressure than they
have ever been."
But the results nag at him, "I have kids, sons 8 and 5," Bailey says, "In my quiet moments, I feel better about offering ACQ than CCA. I feel that our industry has to change eventually. And the reason is arsenic."1
In a publication by the Environmental Protection Agency (EPA) of the United States called Chromated Copper Arsenicals (CCA) and its Use as a Wood Preservative the question of alternatives was answered in this way. "Since CCA treated wood does not pose a significant risk to human health and the environment, EPA does not recommend replacement solely on that basis. When selecting materials to use for decks, playgrounds, and other outdoor uses, consumers and communities should consider other factors in addition to the environment, such as cost, strength, and durability. From an environmental standpoint, however, the production of plastic, steel, and concrete also have environmental impacts that should be considered when choosing a material."27
The next question on this sheet is "What is the EPA's position on the findings of a recent study conducted by Dr. David E. Stilwell and Katja Gorny of Connecticut Agricultural Experiment Station in New Haven, Connecticut, which suggests that arsenic is being released from decks and playground equipment made from CCA treated wood into the soil below?"27
Here is the startling answer, "The Agency has reviewed Dr Stilwell's recent article and, to assess the significance of its findings, has requested all the data generated as part of his study. It is worth noting that, over long periods of time, almost any wood preservative may be released in minute amounts as the wood weathers. In addition, any sampling of arsenic in soil must take into account the variability of naturally occurring levels of arsenic already present in the soil. Following EPA's review of the complete study, the Agency will be in a better position to determine its significance and to take any action necessary to protect public health."27
In an article published in Today's Homeowner in the July/August 1998 issue written by John D. Wagner called Decking Decisions28 we are given some alternative choices to CCA treated wood.
Advantages: Now more widely available, ipe (E-pay) is a durable teak-like tropical hardwood sold as Ironwood or Pau Lope (pow-Low-pay). Twice as strong as oak, ipe is more durable than redwood and cedar. It has a life expectancy of 40 years or more, and is resistant to insects and decay. Ironwood is backed by a 25-year transferable warranty, while Pau Lope comes with a 20- year limited warranty. All grades are virtually knot-free, and tight grain patterns make this wood impervious to water. Another tropical hardwood option is cambara; it's less durable to ipe but also knot-free.
Disadvantages: Expensive. Requires predrilling for fasteners.
Availability: Ipe is available in most standard dimensions, including 5/4 x 6 in. For deck tops and 2 by dimensions for handrails, joists and posts. But delivery can take up to three weeks.
Recommendations: Treat it just once with a UV-blocking sealer like Penofin and let it weather. Use stainless steel screws.
Cost: About $22 per square foot installed, not including substructure. Decking itself costs about $5 dollars per sq. foot. Cambara decking costs about $3 per square foot.
Redwood and Cedar
Advantages: Redwood and cedar heartwood has glowing color, handsome straight grains and natural resistance to rot and insects. Boards are very easy to cut and can be left untreated to weather naturally. Life span is easily more than twenty years.
Disadvantages: Both are expensive. Redwood sapwood--the newer wood closer to the bark--rots when exposed for sustained periods to moisture. Cedar sapwood breaks down quickly in moist conditions.
Availability: Redwood and cedar are sold in all standard dimensions. Cedar 5/4x6 in. Deck boards are easy to find. Redwood can take a few days for special orders.
Recommendations: For redwood, use kiln-dried deck heart or deck common. Clear heart, clear, B heart, and B grade redwood are fine for lower budgets. For cedar, clear all heart is the premium choice. Good, lower-cost alternatives include appearance grade and for dry areas, No. 1 select tight knot (STK). Use hot dipped galvanized, aluminum or stainless steel (ring-shanked) nails, screws and other fasteners.
Cost: About $18 to $22 per square foot; the higher grades of redwood cost much more.
Advantages: Virtually indestructible, plastic-wood composites blend 30 to50 percent recycled plastic with wood fibers for skid resistance and stain-ability. Composite lumber is low- maintenance, and resists rot, insects and UV rays. It's also splinter- free and easy to work with. Deck screws sink in and disappear. Trex, TimberTech and DuraWopood Ex come with 10-year warranties, while ChoiceDek and DuraWood PE are backed for 20 years.
Disadvantages: Some composite lumber has a plastic appearance and some colors fade over time. During construction, sawdust and shavings must be collected in a drop cloth because they aren't biodegradable. What's more, not all composite lumber can span traditional 16 or 24 in. joist spacing; narrower joist layout may be needed, boosting cost. Some building codes don't allow composite lumber; check with your building department before ordering.
Availability: Trex, approved by most building codes, is sold in most standard dimensions, including 5/4x6 in. and 2-by. Choice Deck and Smartdeck come in 5/4 by 6 in. Timber tech is 1 ½ x 6 and 1 ½ x 8.
Typical choices are plain deck boards (which you install) and SmartDeck's Durawood EX (installed by a certified contractor). SmartDeck also offers a 100 percent plastic product, called Durawood PE. If you are wiring the deck, consider ChoiceDek and Durawood; both of these deck and rail systems are formed to allow running wires within posts or deckboards. Composite lumber weathers to a light gray and can be painted or stained, though protective sealers aren't required, use galvanized screws.
Cost: About $20 per square foot installed for Dura wood Ex, not including substructure. Most composite lumber by itself costs around $3 per square foot.
Vinyl Deck Systems
Advantages: Installed by you or a contractor, vinyl deck systems typically include deck boards, rails, spindles and fascia. They create a low- maintenance deck that needs no sealers or finishes and is free of splinters and cracks. Planks have good spanning ability and resist UV rays if treated at the factory. Fasteners can be completely hidden once planks are installed. The three major manufacturers of vinyl deck systems Kroy, Dreamdeck and EZ Deck offer limited lifetime warranties.
Disadvantages: These systems are relatively expensive. Vinyl can fade and get brittle with age unless specially treated at the factory, and all vinyl eventually loses it's gloss. Sawdust isn't biodegradable so it must be collected in a drop cloth.
Availability: Kroy deck planks come in 8 in wide, DreamDeck planks are 5 ½ in wide and EZ Deck planks are 4 or 6 in. wide. These systems must be ordered through distributors.
Recommendations: Choose skid resistant planks, available in a variety of colors from Kroy, Dreamdeck and EZ Deck. Also opt for colorfast, no-fade treatments like the one used by EZ Deck. Planks can be cut to length by a circular saw; plank ends are covered with vinyl caps. Proprietary strip systems are screwed to joists with galvanized or stainless steel screws, then planks snap into place.
Cost: About $13 per square foot installed for Kroy, $18 for Dream Deck and $22 for EZDeck, not including substructure. Decking itself costs about $7 to $12 per square foot.
In an article, titled Does Pressure-Treated Wood Belong in Your Garden, published
by Kitchen Garden in July 1998 and written by Ruth Lively we learn some additional
choices. She suggests "Check out the locals. Depending on where you live,
you may have access to a native species whose heartwood is decay resistant.
Black locust, red mulberry, osage orange, and Pacific yew show outstanding longevity.
Other highly rot-resistant species include catalpa, Arizona cypress, juniper,
mesquite, and several oaks, namely bur, chestnut, Gambel, Oregon white, post,
She also informs us of the new safer pressure-treated wood. "Public concerns over potential hazards of CCA has led the industry to look for safer, less controversial preservatives touted as environmentally sound. ACQ is a mix of and a quaternary ammonium compound, nicknamed quat. Small amounts of copper and quat do leach, but nothing in ACQ is considered hazardous by the EPA, and no ingredient is a known or suspected carcinogen. The maker, Chemical Specialties, Inc. (CSI), uses only recycled copper in ACQ. The wood is expected to last as long as CCA-treated lumber.
I (Lively) first heard about ACQ four years ago, but never found a place to buy it. Why, I wondered, was it so unavailable if it had so much to recommend it? The first version to go on the market contained no water repellent and had to be treated by the buyer to minimize cracks and warping. In late 1997, CSI came out with a version, ACQ Type D, which has a built-in water repellent. The company hopes the new formulation will be more attractive to lumber retailers and consumers. ACQ-treated wood is about 10% more expensive than CCA because it contains more copper."15
Here's what the Environmental news Network has to say about ACQ in their article. There's ACQ Preserve lumber to choose from. Also a pressure-treated wood, ACQ lumber is treated with a greener blend of ammonia, copper and quaternary ammonia. These ingredients won't earn ACQ lumber non-toxic status, but they do replace the more seriously toxic arsenic and chromium products that taint other outdoor woods."19
In an article published by the Environmental Building News we read, "although
ACQ and other less toxic alternatives to CCA have been in the works for years,
they have not been promoted for fear of feeding consumer concerns about the
dangers of CCA."16
Home | Previous | Table of Contents | Next