Considerations that Influence Exotic Hardwood Decisions
Exotic hardwood evokes gorgeous mental images of indigenous wood species: Brazilian Cherry (Jatoba), Brazilian Teak (Cumaru), Tigerwood and Santos Mahogany. The range of exotic hardwoods available does present a dazzling array of choice. However, builders and consumers must deeply invest in the knowledge needed to safely protect any investment in exotic hardwood flooring installation. Wise choosers must consider two wood fundamentals: woods specific gravity and moisture content.
Specific Gravity (SG) is a physical property of wood that is an index of weight. The SG of wood is usually based on the volume of wood at some specified moisture content and its weight when ovendried. Many factors influence the woods SG. For exotic hardwoods, it includes: the tree's genetic factors, where the wood was located within the tree itself and conditions at the tree's on-site location. Magnify all of the above by global environmental diversity, and you begin to sense the need to thoroughly research prospective exotic hardwoods.
Wood species contain their own properties and characteristics. Softwoods have SG’s which can vary significantly from hardwoods. However, density varies enough within the hardwood species to caution us on this issue. Black Walnut's wood SG rating varies by 9 percent from that of White Ash, for example. While this makes for delightful hardwood diversity, builders and consumers just need to be aware that such differences also occur in exotic hardwood species.
The Exotic Challenge
Brazilian Teak also known as Cumaru is an excellent example of exotic hardwood flooring challenges. Its popularity comes from its extreme hardness and durability characteristics so it can be used in both commercial and residential flooring applications. However, it may resist oil finishes and not dry properly. Builders would be exotically challenged to determine what the stable, dependable moisture content measurements for the flooring material should be previous to installing the finishes and after the finishing operation. Pre-finished wood flooring should be purchased by the builder, consumer or the installer in this application unless they are well trained in finishing these type of exotic wood pieces. This woods susceptiblility to moisture could have a huge impact on the installer's schedule, the finishes he uses and the long-term viability of the floor itself.
Moisture Content Diversity
Wood's moisture content (MC) also exerts a powerful influence over the success of exotic hardwood flooring installations. As of early 2012, the industry has not developed universal grading standards for exotic hardwoods. That means consumers must rely on quality manufacturing by the manufacturer of the flooring. Also, manufacturers who produce mixed-and-matched exotic engineered hardwood floor products face the difficult task of managing varying moisture content characteristics for each species in the mix. Put simply, mixed-and-matched wood flooring requires much greater investment in measuring for the equilibrium moisture content (EMC) - wood's stable moisture status - than single-species flooring.
That said, installers are able to purchase accurate wood moisture meters which have different wood specific gravity settings and corrections tables for exotic hardwood applications. Meters, such as Wagner's MMC220, has Extended Range Specific Gravities available which enables flooring professionals to customize assessments for the correct moisture content in tropical wood species.
Exotic hardwoods, by definition, are as distinct and diverse as our motives for choosing them. Different species contain different wood specific gravity traits. Even organic and inorganic wood extracts have different densities in the tree's heartwood (its internal core) and the sapwood (its outer layer beneath the bark). Proceed, but enhance your grand vision with fundamental knowledge before pulling the trigger on your exotic hardwood decision.