Choosing the material to build a boardwalk out of can be tricky. Never mind the amount of people traipsing over the thing; being located on the shore, it is subject to salt spray. And in a place with four seasons, the wood is subjected to brutally humid summers and freezing cold winters.
So what did people make boardwalks out of, in the days before pressure-treated lumber? In the late 1800s Atlantic City put up the first large-scale public boardwalk in the United States. For material they used Atlantic White Cedar, conveniently harvested from New Jersey's nearby forests. Technically not a cedar at all, but a cypress, the tree grew well in wet areas and was naturally rot-resistant.
Ironically, these excellent properties are what made the wood an unsustainable choice. In a 1934 book called "Trees You Want to Know," American botanist Donald Culross Peattie wrote that Atlantic White Cedar would "endure moisture indefinitely," and wood that weathered well was in demand; lots of folks began using it for fencing and roof shingles. As it became popular, we started overlogging it, and soon it became both expensive and scarce.
Atlantic City thus had to find a different wood to maintain, repair and update their boardwalk, and they switched over to Western Red Cedar. The stuff was also pricey because it had to be shipped in from the Pacific Northwest, but it was easier to get than Atlantic White Cedar; and being a rainforest wood, it dealt well with moisture.
The rise of pesticides changed the wood game after World War II. By the 1950s Atlantic City had switched materials once again, this time going with chemically-treated Southern Yellow Pine. Relatively affordable, this is the same stuff that wooden roller coasters, like Coney Island's famous Cyclone, were made of.
Speaking of Coney Island, we can assume they followed the same wood "diet" for their boardwalk erected in the 1920s, though we don't know for sure. What we do know for sure is that Coney Island's boardwalk, officially called the Riegelmann Boardwalk, was the first to switch over to a tropical rainforest wood. In the 1960s they began using Ipe, and Atlantic City followed suit.
Ipe ain't cheap—also called Brazilian Walnut, the stuff has to be shipped in from Central or South America—while chemically-treated Southern Yellow Pine was easily available and relatively affordable. So why the switch? Because boards made from Southern Yellow Pine needed to be replaced every ten years, bringing with it high maintenance costs. Pricey but hard-wearing Ipe was reckoned to last for 25 years. At some point, some bean-counter worked out the math and the switch was made.
Ipe is strong, dense, and super-durable. It's rot-resistant, insect-resistant and even naturally fire-resistant, and the boards laid at Coney Island did indeed last for two and a half decades before needing to be replaced.
However, there will not be another wood replacement cycle at Coney Island. Amidst stiff opposition, the NYC Parks Department has announced that the Boardwalk will now be topped with concrete and recycled plastic formed to look like wood. The Parks Department cites the environmental concerns of continuing to harvest tropical rainforest wood and the maintenance costs; preservationists argue that natural wood is an essential ingredient of the Boardwalk's very identity. Just yesterday there was another rally in Brooklyn protesting the plan.
Pentagram Design's Paula Scher, a member of the Public Design Commission tasked with assessing the plan when it was announced in 2012, then told the Times:
"If you think we're happy that wood is being replaced by material we find less appealing, that is certainly not the case.... It's called a Boardwalk, and if you use other material, it loses its identity. I understand that, but it's so much better to have a surface to walk on next to the beach.
"We love our icons of the past, and sometimes you can preserve them," Ms. Scher said, but "things have changed."
Some materials, of course, change more slowly than others. The plastic stuff will reportedly last for 75 years.