If you actually desire gray decking, you probably realize that you’ll eventually get it, if you simply go with a no-maintenance approach to your deck. But you probably don’t want your decking to appear gray. Either way, you need to know this: No matter how high end you go, any lumber species will fade in the sunlight; some also undergo chemical changes that create even more of a color change. While many factors play into how long it takes for wood to mature, the fact remains that the initial color of your brand new deck will change over time — unless you do something about it.
Beneath the gray exterior of weather-beaten wood, there’s still a fresh surface that could be exposed through sanding or planing. By removing the gray outer layer, you can actually reveal the color that matured lumber once displayed. How long a species takes to turn gray depends in part on its oil content; since many tropical decking species contain a high amount of oil, it takes longer for the sun to bleach the surface and dry out the boards. The extra natural resin resists that drying process, as can added decking oil that can be applied as part of regular decking maintenance. (This is the very reason why we refer to tropical decking as a low-maintenance product, rather than a maintenance-free one.)
In addition to the natural weathering process, some species undergo unique chemical changes. While Cherry isn’t a species typically used for decking, it is the most well-known example of this chemical reaction. Another interior species, Mahogany, also reacts strongly over time. The only decking species that undergoes a similar change regardless of sun exposure is Teak. Essentially, the cause is a combination of species and soil chemistry and particularly the presence of lignins and extractives. (We’ll go into greater detail about those components in another article.)
Added Results of Sun Exposure
In addition to the color change caused by exposure to the sun, surface cracks or checks typically occur. Especially if subjected to intense, direct sunlight, surface checks are inevitable for wood. But you need to know that these tiny cracks are not defects; rather, they naturally occur whenever wood dries quickly and unevenly.
Attempts at Color Matching
If you have an older exterior structure that has been weathered, attempting a color match with a new structure will be somewhat impossible. However, over time, the sun will bleach your new application, causing it also to go gray. Commercially manufactured bleaching oils can be used to speed up this natural process, but many lumber experts believe that the effect those bleaching oils achieve is inferior to the weathering produced by nature’s own combination of water, wind, heat, UV light, and longer wavelength light.
At the end of the day, nature will have its way with your deck, over time turning it gray unless you treat it in ways that prevent such bleaching. Some color change will be inevitable, either way. The unique natural beauty of wood is something to appreciate though, rather than comparing it to synthetic products or photo-shopped images. And like all of us, the allure of natural wood's beauty changes as it matures.