As with many other products, the history of decking in the US is an interesting one. For many years, the woods of choice were Redwood and Western Red Cedar, both from the western region of the country. With the advent of the Green movement and the controversy about the Spotted Owl, the production and availability of these species was greatly diminished and the market was in need of a suitable replacement. The national trend to enjoy the outdoors, barbecue grilling and gardening was coming strong and, combined with the growing pattern of the economy, the demand for decking has substantially increased. People also realized that a nice deck increased the value of their homes, besides providing a great place to entertain family and friends.
The answer was S.Y.P. - Southern Yellow Pine, a readily available, fairly inexpensive group of species coming from big plantations in the Southern states, primarily used - after vacuum-treated for added durability - for all sorts of construction purposes. SYP quickly dominated the market because of its ample supply and lower cost, but it was not the right wood for the application, primarily due to its low stability and aesthetics, plus the use of chemicals, which also brought environmental concerns.
Decking is probably the harshest and most difficult application for wood because, contrary to siding, which also receives sun and rain, the water does stay on its horizontal surfaces and allow for the double-punch from the elements. First comes the UV rays of the sun, which damages the surface cells of the wood (greying is in fact the first step of decay) and that allows for water penetration, which usually causes the most damage to the wood, even when it is treated with chemical preservatives.
Then some clever industrialists, realizing the market potential, came up with the idea of mixing wood residues (mainly saw-dust) to plastic resins and/or recycled plastics and developed a fairly decent product for exterior decking, with very aggressive marketing and distribution, thus taking (and still growing) a substantial market share. With time, pure plastic or vinyl decking was also been offered and today it is a solid industry. However, it is not a natural product and people still favor the look and feel of a good wood. Also,
these products are subject to the erratic fluctuations of oil prices, which may be worse in the future, as the world population continues to grow and the pressures against oil and its by-products continue to get stronger.
The obvious answer to composite or plastic decking or the inferior SYP counterpart was tropical hardwoods. The species being sold for decking are naturally very hard, dense and extremely durable, besides the inherent beauty of their colors, texture and grain patterns. The green movement has also helped, by demanding sustainable products of legal origin, which is now the rule worldwide for the supply of tropical hardwoods. New, lesser-known species are coming to the market and they are very competitive in price, offering true value for customers. This is probably a long-lasting trend in the marketplace, especially because the interior flooring industry is also offering many tropical species, with more colors and design patterns. People certainly want to make their houses beautiful.
All the wood (except Ipe) is carefully kiln-dried to an average moisture content of 15%, thus preventing excessive movement of the boards and minimizing surface checks.
The decking is supplied kiln-dried to an average of 15% MC and is intended for exterior use only. It should be stored away from direct sun light and allowed to acclimate to local moisture levels before installation.
Cutting and Drilling
High-quality drills or saws, with premium carbide tipped saw blades or power tool bits are recommended for decking products. Edge boards should be pre-drilled on faces and screwed to the joists for extra strength of the structure.
Ends should be sealed immediately after cross-cutting using a clear aqueous wax end-sealer, in order to reduce end-checking.
High-density plastic, stainless steel or coated metal fasteners, together with stainless steel screws, are recommended because of its corrosion resistance and holding power. Coated metal are naturally less durable and may stain the wood. There are several hidden clip systems in the market and it's use is a matter of personal preference.
All standard sizes – 5/4 x 6, 5/4 x 4, 1 x 6 and 1 x 4 decking may be installed on 16” on-center joists, but always under the regulations of local building codes. 5/4 x 6 may also be installed on 24” on-center joists. Installation with a diagonal pattern will require shorter joist spacing. A gap of 1/8” is the norm between boards, for air circulation and allowing movement of the wood when seasoning.
The decking comes factory finished all four sides with a high-end coating for extra-protection and durability. Re-finishing with a good and recommended commercial coating sold by a reputable merchant or manufacturer will be necessary as soon as the wood starts to fade or change the original color. Do not let the wood turn gray as this is the first sign of decay, as surface cells are being damaged by UV rays of the sun and allow for water penetration.