First, what are the species generally available for flooring choices? Temperate hardwood species from the United States and Canadian forests are the most readily available and overall are considered the most environmentally responsible. They are generally manufactured according to a recognized standard such as NOFMA: The Wood Flooring Manufacturers Association, which certifies manufacture of flooring that includes the species- both red and white oak, hard maple, beech, birch, hickory/pecan, ash, cherry, and walnut. The MFMA (Maple Flooring Manufacturers Association) also administers manufacturing standards for hard maple, beech, and birch primarily for sports floor applications. The CLA (Canadian Lumberman's Association) has voluntary grading guidelines for red and white oak, maple, and birch. Also, most of the lumber comes from forest that are managed to meet sustainability criteria.
Some softwood species are also available for wood flooring. New wood as well as old recycled building members are made into flooring. These species may be made with allowance for a wide range of moisture content and should be checked by the contractor prior to installation to determine proper installation and related acclimation.
Ash is more dimensionally stable than oak, is generally as hard, with a similar grain pattern and finishes similarly to oak. Ash is a good choice where a very light color or a white floor is desired. The NOFMA Clear and Select grades should be selected since they require these separations to include mostly white sapwood. A draw back or caveat when selecting wide widths for a white floor with a wide range of seasonal variation is that noticeable gapping is likely. Customers should be informed of this during the selection process.
The other temperate hardwood species choices have their own unique characters. Locust is very hard, has an iridescent component, and glows in black lights. Mesquite is generally selected for its chocolate heartwood color, and the sapwood is vulnerable to insect attack. Alder is light in color that changes to reddish tint with age, is soft and stains poorly. Elm is selected because of the unique flame characters within the grain pattern.
Imported species come in a myriad of colors, graining, and physical characteristics. One of the keys in selection is to identify the actual species selected. Many of the names are marketing names or common names and include two or more species. The differences within these classes can be quite different region to region. So what is expected may be different from what is received. For this article imported species will not be discussed.
What "look" does the customer want in a flooring product?
What activities will occur on the flooring?
What environmental conditions will be established?
The "look" such as light or white or dark to ebony can be accomplished by staining those species that will stain or by selecting a naturally white or naturally dark wood. Other characteristics such as grain and color as noted in the foregoing descriptions will also direct the species choices. The oaks and ash species have a virtually unlimited color pallet when using stains.
The traffic and conditions surrounding the site will help determine whether wear is an issue. Harder materials should be the options for heavy traffic and abrasive conditions. The environment associated with the site also qualifies the species options. The options for width will be determined by the stability. For wide ranging environmental conditions those more stable species and the more narrow widths are the best choices. This can apply particularly with radiant heated flooring where shrinkage may be an issue. Also, for assurance of quality and proper manufacture select a certified NOFMA hardwood product, an MFMA stamped maple, birch or beech product, a CLA member's oak, birch or maple product, or an SPIB stamped softwood.