Public boardwalks are increasingly choosing composite decking as their preferred option. Environmental activists are exerting pressure on city planners, and many of them are caving in to opt for less expensive composite decking. But there are several significant issues to be aware of in regards to composite decking, especially when using that to construct boardwalks. Let’s consider why using tropical decking like Ipe or Cumuaru wood is instead a much better choice.
Lower Hardness Rating
Comparing tropical wood like Ipe or Cumaru to composite decking is almost like comparing daytime to night time. Which option is the hardest? We’re talking ten times harder or even more! Although the mild hardness of composite decking may be acceptable for a deck on a private residence, hardness is crucial for a public boardwalk where thousands of people walk on it every day.
We are all aware that plastic is notorious for retaining heat and that it can get extremely warm to the touch when placed in the sun. People may not be aware, however, that composite decking is primarily constructed of plastic. For the outer layer, some manufacturers use pure polyethylene – the same plastic used for disposable water bottles – while others combine plastic with wood flour.
That might not be a major concern in a residential backyard with canopies, awnings and tree coverage, but if composite decking is placed on a public boardwalk, that area is typically exposed to harsh sun all day.
Another reason why you shouldn’t entrust such a large job to plastic is that as plastic warms up, it releases gas byproducts that eventually weaken and degrade the material. Plastic will continue to degrade even after the sun has set, because it stores heat for a long time even after exposure to sunlight has ended.
We’ve already talked about how fundamentally plastic is used to create composite decking. It is therefore oil-based. As we well know, a boardwalk located beside the ocean or a lake or river will inevitably get frequently wet. Since water and oil don’t mix very well together, water on composite decking tends to make the surface slick. Faux wood grain may initially help with the problem by adding a little extra texture, but as the plastic degrades, it might actually weep oil, and no amount of roughness will be able to compensate for that. A recipe for disaster is undoubtedly created when boardwalk-friendly food, sunblock, and surf wax are added. Once more, the city potentially faces a liability dilemma.
We cannot halt wood movement, but we can anticipate it and make allowances for it. Composite decking, which is essentially constructed of a significant amount of plastic, offers unpredictable expansion and contraction. Its wood flour core also moves because it is constructed of wood. However, because it lacks the solid wood’s grain structure to control that movement, the core extends along each “board.” The outer shell also enlarges as a result. However, the plastic remains stretched while the core shrinks. Uneven warping results from the ensuing space between the core and the shell, with the exposed ends expanding more than other regions. This scenario causes swelling across a broad boardwalk, not just at the ends but also at a number of locations in the middle.
Continue reading with Part 2.
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