A tour of some of the State’s popular parks—and a bad experience with an old Florida deck—makes the case for composite decking.
I’ve just completed day 10 of a dose of antibiotics.
Ironically, I ended up injured during a short visit in Florida, photographing and examining the State’s most common types of outdoor decking. A friend showed me a crumbling deck in Gainesville, made of treated Southern Pine in his back yard, long past its expiration date.
“We can take that out of there in half a day,” I suggested. The process, like any demolition, was not as clean as I had hoped. While the 15-year-old deck screws reversed out cleanly, looking brand new, half of them were oversunk into the rotten wood, making them impossible to find. In part, the wood had swelled. In part the installers over-drove them. Long story short, to find the screw heads, I had to hammer and claw away chunks of blackened, treated wood. One of those poisoned daggers sunk an inch into my hand, and the wound immediately became infected.
Ironically, I had been traveling to some of the State’s most popular outdoor parks and preserves, to compare how boardwalks and hardscapes handle demanding environments. My injury reinforced my general observation. The age of treated lumber (should be) over. Long live plastic composites.
Today’s composite plastic products, it should be noted, are much improved over brands available in the early 1990s. At that time, the industry went through some upheaval, and changed how composite decking is made, removing some wood fillers from the mix of certain products, and adding a cap layer that solved several durability problems.
CCA: A Toxic Legacy
According to research at the Univ. of Gainesville, the amount of discarded copper chromium arsenic (CCA)-treated wood was expected to peak in about 2015. This fits with my anecdotal observations. Decking at both state and municipal sites is reaching the end of its service, life, or already past it. Millions of board feet of CCA are headed for C&D landfills in the State. That’s a major environmental concern.
According to an article published in Waste Age back in 2001, In Florida, specifically, CCA has not been closely regulated, in part because a federal regulation lets this material off the hook. “Part 261.4 of the Code of Federal regulations exempts: “Solid waste which consists of discarded arsenical-treated wood or wood products which fails the test for the Toxicity Characteristic for Hazardous Waste Codes D004 through D017 and which is not a hazardous waste for any other reason if the waste is generated by persons who utilize the arsenical treated wood and wood product for these materials’ intended end use.”
The same article noted that in 2001, CCA accounted for about 80 percent of the decking market nationally. And even then, concerns about leaching extended into home landscaping, where unsuspecting homeowners purchase mulch that may contain ground CCA, which leaches especially rapidly into soils.
“Red mulch is very popular in Florida,” according to Bill Hinkley, then chief of the bureau of solid and hazardous waste for the Florida Department of Environmental Protection (FDEP) in Tallahassee. “To create the mulch, producers chop a 1-inch chip from a mixed wood stream, which includes C&D wood waste, untreated lumber, oriented strand board (OSB) and particle board, then dye it for decorative or commercial landscaping use.”
But the problem of how to safely dispose of CCA-treated wood is just one of several good reasons that planners in Florida should immediately phase out its use in favor of modern composite products.
Another good reason is cost. There’s a common misperception that treated lumber is a more affordable alternative to plastic-composite decking. Before we look at those numbers, let’s look at life cycle.
How Long Does CCA Really Last?
Treated wood, according to AWPI, has a lifespan of 20 to 50 years, but in the field, particularly in wet and warm environments, that’s almost never the case. Decks as new as 10-15 years old that I saw and photographed in Florida frequently showed major degradation. And according to some research, as many as half of all decks in the U.S. may be past their “useful life” and unsafe.
While visiting North Florida I recorded the condition of decks and boardwalks in numerous parks, outdoor boardwalks and historic sites—most of which chose CCA wood over composites. What I found was a large percentage of materials nearing the end of their useful life. By “useful,” I don’t mean they’re necessarily on the verge of structural failure, but the surfaces have become untenable. Splintering, cracking, spalling, shrinkage, and oxidation are common. These boards are no place for flip-flops and casual footwear. The railings, and especially posts made of CCA wood are often even worse, especially when end grains are not protected by waterproof caps.
CCA-treated lumber can last longer, but only if it’s carefully maintained. That means regular cleaning and coating with water repellant paints, stains or preservatives. This technique typically adds about 5 years to the material’s durability, but as you can see from the photographs, as protective coatings wear off, the wood quickly deteriorates. CCA wood coated at regular intervals, according to deck experts, could last up to 40 years, but this method requires extreme diligence and a lot of regular labor.
Also, coatings made with solvents or acrylic have a high embodied footprint. This environmental impact has to be added to the overall resource intensity of the CCA, along with its final disposal. The result is that the product is not especially sustainable, other than the fact that the wood itself is renewable.
CCA vs. Plastic: Life Cycle Economics
When you reduce the exaggerated lifespan figures for CCA, composites begin to make sense from a cost perspective. Assume an installed cost for CCA-lumber of roughly $8 per sq. ft. Now look at Trex, one of the most sustainable composite brands, with installed costs of about $12 per sq. ft. That’s about 30 percent more than CCA lumber. But the economic analysis too often stops here, instead of looking out at the life-cycle costs of each product.
The only real maintenance for a plastic-based composite deck, by comparison, is occasional cleaning. Many brands now come with a 25-year fade and stain warranty. But you can realistically expect a composite deck to last well past that mark before needing actua
l replacement. If you factor in the labor and coatings costs, life cycle costs of composites can be 40 to 50 percent less than CCA.
In 2013, Consumer Reports estimated that the cost for maintaining a CCA-treated wood deck for 10 years is $5000. Compare that to the $50 annual maintenance cost for composites, and there’s no contest.
Time for Transition
The time for Florida to transition to more sustainable, durable hardscapes is right now. Millions of board feet of CCA decking are reaching the end of their useful life.
Disposal of that vast quantity of potentially hazardous waste is one part of the challenge. Replacing it with something better is the other. I urge any State Agency, museum, park managers or homeowners looking for new hardscapes to look first at recycled plastic composite materials. The age of CCA is over. It’s time to make way for a cleaner, more economically prudent alternative.