| MASTERSPEC - EVALUATIONS | 05/03 (R 05/05) |
The following editing instruction relates directly to specific parts of the Section Text where it is referenced by the applicable Editing Instruction No. in the editor's notes:
Wood flooring is a highly visible building finish that receives significant wear and abuse, and impacts on the safety and comfort of occupants. It is subject to abrasion, water, dirt, and cleaning agents. When selecting wood flooring products and finishes, consider the following:
The durability of a wood flooring installation depends on the wood species, grade, cut, and the finish selected.
Technical, installation, and maintenance information for wood flooring is available from associations representing manufacturers, distributors, dealers, and contractors. Contact the organizations listed below for literature that is offered free of charge to specifiers. Their Web site addresses are listed in the "References" Article in these Evaluations.
Generic specifications are feasible for unfinished, solid-wood strip and plank flooring covered by standard grading rules. Standard grading rules do not apply to woods less commonly used for flooring, antique woods, and imported woods. For these products, specify acceptable manufacturers or specify that the grade and cut match a representative sample.
Name acceptable products to specify wood flooring that cannot be categorized with precision, such as wood flooring that is parquet block, factory finished, or engineered. For competitive pricing, name several manufacturers' acceptable products.
Wood flooring is either solid or engineered wood and is available in strip, plank, and parquet form.
Species of wood available vary among manufacturers and product types. The Wood Flooring Tables in these Evaluations, which are categorized by product type, list the species of wood available from each listed manufacturer.
The hardness of a wood species is its ability to resist indentation, wear, and marring. The Forest Products Laboratory (FPL), a unit of the research organization of the Forest Service, Department of Agriculture, reports the side hardnesses of species. Side hardness values are the average pounds of pressure required to embed a 0.444-inch- (11-mm-) diameter, steel ball 1/2 its diameter into the wood with the load applied perpendicular to the grain. Values are the average of radial and tangential penetrations. These values are sometimes called the Janka hardness of wood. The following table shows the average side hardnesses of domestic and imported species in a dry state according to FPL's Wood Engineering Handbook, 2nd edition, and various and manufacturer's technical data.
| WOOD SPECIES | SIDE HARDNESS LOAD PERPENDICULAR TO THE GRAIN |
|---|---|
| Ash, White | 1320 lbf (5870 N) |
| Beech, American | 1300 lbf (5780 N) |
| Birch, Yellow | 1260 lbf (5600 N) |
| Cherry, African* | 1110 lbf (4900 N) |
| Cherry, Black | 950 lbf (4230 N) |
| Cherry, Brazilian* | 2280 lbf (10 140 N) |
| Cypress, Australian | 1375 lbf (6120 N) |
| Douglas Fir | 660 lbf (2940 N) |
| Hickory | 1820 lbf (8100 N) |
| Maple, Black | 1180 lbf (5250 N) |
| Maple, Hard | 1450 lbf (6450 N) |
| Oak, Northern Red | 1290 lbf (5740 N) |
| Oak, Red Southern | 1060 lbf (4720 N) |
| Oak, White | 1360 lbf (6050 N) |
| Pecan | 1820 lbf (8100 N) |
| Pine, Eastern White | 380 lbf (1690 N) |
| Pine, Southern Yellow (loblolly and shortleaf) |
690 lbf (3070 N) |
| Pine, Heart (longleaf) | 870 lbf (3870 N) |
| Walnut, African* | 1290 lbf (5740 N) |
| Walnut, Black | 1010 lbf (4490 N) |
| Walnut, Brazilian* | 3680 lbf (16 370 N) |
| Walnut, Peruvian* | 1080 lbf (4800 N) |
| *Imported wood species | |
Standard grading rules for solid-wood strip and plank flooring vary among industry organizations and for wood species. There are no standard grading rules for certain woods that are infrequently used for flooring or for recycled and imported woods. Some manufacturers establish their own grading systems, using the same or similar terms as those used by industry organizations' grading standards.
Sizes of solid-wood strip and plank vary with the grade and species. Not all face sizes or thicknesses are available in every grade or in every species. Consult manufacturers or suppliers for available dimensions.
MFMA and NOFMA standard grading rules are available, free of charge, on their Web sites, which are listed in the "References" Article in these Evaluations.
The West Coast Lumber Inspection Bureau publishes grading rules for Douglas fir, Western hemlock, Western red cedar, white fir, and Sitka spruce.
The cut of solid-wood flooring affects its appearance, durability, and dimensional stability.
Moisture absorption and emission cause wood to expand and contract. Generally, the most significant dimensional change occurs parallel to the grain (tangentially). The dimensional change across the grain (radially) is about one-half that of the tangential change, and the change along the grain (longitudinally) is slight.
A cut producing grain perpendicular to the board face minimizes the distance between growth rings on the face and exposes the least amount of the spring growth of the wood (springwood), which is less dense than its summer growth (summerwood). Therefore, a cut producing grain perpendicular to the board face is the most durable cut. It is also the most dimensionally stable because the maximum shrinkage and swelling occur across the board's thickness rather than across its face width.
Only oak is generally available quartered or rift sawn. For increased dimensional stability, solid-wood parquet flooring manufacturers gang rip plain-sawn boards through their thicknesses. The ripped pieces of plain-sawn boards are turned and become thinner quartered parquet blocks.
The Hardwood Plywood & Veneer Association (HPVA) publishes HPVA EF, Engineered Wood Flooring. This standard establishes requirements for grade of plies, moisture content, machining, bond line (delamination resistance), construction (ply assembly), formaldehyde emissions for products made with urea-formaldehyde or melamine-formaldehyde adhesives or surface coatings, and finish of engineered-wood flooring. Veneers for the face ply can be of one or more species. Common species used include pecan, hard maple, red oak, white oak, birch, ash, beech, black walnut, southern pine, and black cherry. Veneers are rotary cut, sliced, or sawed from a log, bolt, or flitch. Sawed veneers are the most durable and look the most like traditional solid-wood flooring products.
Face Grades established by HPVA EF are summarized as follows:
Wax finishes over penetrating stains are the least-durable finishes available. Generally, they are unsuitable for commercial applications. These finishes are the most susceptible to water damage and require buffing and periodic rewaxing. Wax finishes are factory or site applied.
Surface finishes over penetrating stains are durable and require little maintenance. Oil-modified and water-based polyurethanes are used most. Shellacs, manufactured and natural varnishes, and lacquers are rarely used. Epoxy-ester finishes are very durable and are recommended for gym floors. Moisture-cured urethanes and acid-curing formaldehyde finishes are also very durable but are difficult to apply and have a high VOC content. Generally, water-based finishes are clear and nonyellowing and leave the wood with the most natural appearance. Solvent- and oil-based finishes tend to yellow with age and change the appearance of stained or natural wood. Surface finishes are factory or site applied. Factory-applied urethane finishes are generally cured by exposure to UV light, which is why they are called UV urethanes.
Acrylic-impregnated finishes are the most durable. For these finishes, the wood is saturated with chemicals that polymerize into solid acrylic. Because the chemical reaction occurs throughout the thickness of the wood, it increases the density, hardness, and wear resistance of the wood flooring product. Acrylic seals the wood against moisture and, therefore, increases dimensional stability. Acrylic-impregnated finishes are factory applied.
MFMA authorizes an independent testing agency to test floor-finish products for sports and other surfaces. Test results provide floor-finish comparison and selection data. The list of tested floor finishes is available, free of charge, on MFMA's Web site, which is listed in the "References" Article in these Evaluations.
NWFA's Installation Guidelines: Wood Flooring includes detailed descriptions of various installation methods and procedures and field finishing and repair of wood flooring. This document is available, free of charge, on the NWFA's Web site listed in "References" Article in these Evaluations.
Controlling the moisture content of wood is critical both before and after installation. Wood is hygroscopic, meaning it changes dimensionally with the absorption or release of moisture. Swelling and shrinking varies with the wood species, cut, and type of flooring. Because engineered products' cross-ply construction adds dimensional stability, moisture control for engineered-wood flooring is less critical than for solid-wood flooring.
Manufacturers kiln-dry wood flooring so it will behave predictably. During transit, delivery, and storage, it must be protected from moisture. Before installation, wood flooring must stabilize at (acclimatize to) the temperature and relative humidity of space in which it will be installed. After installation, and even after finishing, fluctuations in environmental conditions cause shrinking and swelling.
Wood flooring installations must accommodate movement. An expansion space is required at the perimeter of the installation. For larger installations, more expansion provisions may be required.
Concrete-slab substrates must be dry and protected from subsurface moisture by appropriate grading and drainage, a capillary water barrier of porous drainage fill, and a membrane vapor retarder. Temperature, relative humidity, and ventilation affect concrete drying time. To dry adequately, a slab allowed to dry from only 1 side generally takes 30 days for every 1 inch (25 mm) of thickness.
Spaces below wood flooring must be dry and well ventilated. Cross-ventilate crawl spaces, and cover the ground with a polyethylene vapor retarder. If solid-wood flooring is installed over wood sleepers on a concrete slab, NOFMA recommends covering the sleepers with a polyethylene vapor retarder and making provisions for ventilating the airspaces between sleepers.
For a comprehensive discussion of the effects of moisture on wood, refer to NWFA A100, Water and Wood: How Moisture Affects Wood Flooring, which is available, free of charge, on the NWFA Web site listed in the "References" Article in these Evaluations.
Verify requirements of authorities having jurisdiction before specifying wood flooring installed on sleepers over fire-resistance-rated floor assemblies. For this installation condition, the International Building Code (IBC) requires fireblocking in concealed sleeper spaces or filling these spaces with an approved noncombustible material such that there will be no open spaces under the flooring that will exceed 100 sq. ft. (9.3 sq. m). IBC makes an exception to these requirements for slab-on-grade gymnasium floors.
VOC restrictions of authorities having jurisdiction may affect the selection of installation adhesives and floor-finish systems. The Section Text places responsibility on the wood floor manufacturers for selecting appropriate adhesives for conditions indicated. The Section Text also includes requirements for low-emitting adhesives required for LEED Credit EQ 4.1 and low-emitting finish systems required for LEED Credit EQ 4.2.
LEED Credit MR 7 requires that a minimum of 50% of wood-based materials be from forests certified by an FSC-accredited certification body to comply with FSC 1.2, Principles and Criteria. An alternative method for meeting the LEED Credit MR 7 requirement is to retain the requirement in Division 01 Section "Sustainable Design Requirements" giving the Contractor the option and responsibility for determining how the LEED Credit MR 7 requirement will be met.
For further discussion of LEED Credits EQ 4.1, EQ 4.2, and MR 7, refer to the Evaluations in the "Sustainable Design Requirements"Section.
Publication dates represent the editions on which the current Section Text is based. Standards are revised periodically, which may occur before this Section is updated again.
The following publications are useful in specifying wood flooring. Other references may be needed for design purposes.
The list of manufacturers is neither a recommendation for the companies nor an endorsement of their products. Verify manufacturers' capability to comply with indicated requirements each time the Section Text is edited.
WOOD FLOORING MANUFACTURERS
Aged Woods Yesteryear Floorworks Company York, PA (800) 233-9307; (717) 840-0330 http://www.agedwoods.com Anderson Floors Clinton, SC (864) 833-6250 http://www.andersonfloors.com Bellawood Colonial Heights, VA (877) 645-5347 http://www.bellawood.com Boen Hardwood Flooring Inc. Martinsville, VA (540) 638-3700 http://www.boen.com Bruce Division of Armstrong Addison, TX (800) 722-4647; (214) 887-2000 http://www.bruce.com Carlisle Restoration Lumber Stoddard, NH (800) 595-9663 http://www.wideplankflooring.com Gammapar Forest, VA (800) 283-5667; (434) 525-5252 http://www.gammapar.com Harris Tarkett Wood Floors Johnson City, TN (800) 842-7816 http://www.harris-tarkett.com Hartco Division of Armstrong Oneida, TN (800) 769-8528 http://www.hartcoflooring.com Heartpine Lumber and Millwork Orangeburg, SC (803) 534-8478 International Hardwood Flooring, Inc. Philadelphia, PA (800) 338-7481; (215) 269-7399 http://www.ihfinc.com Kentucky Wood Floors Charlestown, IN (502) 451-6024 http://www.kentuckywood.com Mannington Mills, Inc. Salem, NJ (800) 356-6787 http://www.mannington.com/residential Memphis Hardwood Flooring Co. Chicksaw Hardwood Flooring Memphis, TN (901) 526-7306 http://www.chickasawflooring.com Miller and Company, Inc. Cahaba Brand Hardwood Flooring Selma, AL (334) 874-8271 http://www.millerlbr.com Oregon Lumber Company Lake Oswego, OR (800) 824-5671 http://www.oregonlumber.com/why.html Robbins Division of Armstrong Addison, TX (800) 733-3309 http://www.robbins.com Sandy Pond Hardwoods, Inc. Quarryville, PA (800) 546-9663; (717) 284-5030 http://www.figuredhardwoods.com World Flooring International Delran, NJ (856) 764-2501 http://www.wflooring.comFLOOR-FINISH MANUFACTURERS
Basic Coatings, Inc. Des Moines, IA (800) 441-1934; (515) 288-0231 http://www.basiccoatings.com BonaKemi USA Inc. Aurora, CO (800) 872-5515; (313) 371-1411 http://www.bonakemi.com Dura Seal Sherwin-Williams Company (The) Upper Saddle River, NJ (800) 364-1359 http://www.duraseal.com Ecolab Inc. Huntington Brand St. Paul, MN (800) 352-5326; (651) 293-1963 http://www.ecolab.com Hillyard, Inc. St. Joseph, MO (800) 365-1555 http://www.hillyard.com Polo-Plaz Coatings National Coatings Company Jacksonville, AR (800) 421-7319; (501) 985-1172 http://www.poloplaz.com
The following tables are based on information from manufacturers' literature, which was current when this Section was updated. No attempt was made to compare various qualities of products. Refer to manufacturers' product data and samples to determine similarities and differences between products. Manufacturers named are neither recommended nor endorsed by the American Institute of Architects or ARCOM. Verify information and manufacturers' capacity to comply with indicated requirements.