Finger Jointed (FJ) MAPLE FLOORING
We recommend maintenance of 6 percent to 9 percent average moisture content following manufacture. Upon receipt of shipment, proper moisture controls must be exercised to maintain proper moisture content.
Edge-grain hardwood flooring is specially selected and consists of pieces in which the annual rings range from 30 degrees horizontal to 90 degrees vertical.
Since hard maple is generally produced from lumber sawn out of relatively small logs with varying knurls, resulting in considerable variation in a single piece, flooring shall be considered to be all edge-grain if 75 percent of each piece falls within the above-mentioned range.
Flooring shall not be considered of specified grade unless the lumber from which the MFMA-FJ flooring is manufactured has been properly kiln-dried.
All MFMA-FJ flooring shall be end-matched unless otherwise specified.
Beech and Birch Flooring
These rules also apply to beech (Fagus grandifolia) and birch (Betula alleghaniensis) flooring.
Finger Jointed Flooring
MFMA-FJ finger-jointed flooring shall include products comprised of one or more individual board segments attached end to end using a series of interlocking fingers and adhesive. Standard MFMA-FJ finger-jointed flooring shall conform to the following MFMA finger-jointed flooring grading requirements:
Finger Joint Design
The finger-joint design shall result in a strength that will insure the product's integrity of its intended use, prior to, during and following installation. It shall produce an appearance that resembles a typical square end joint prior to and following subsequent sandings.
End Segment Criteria
End segments shall be 6" minimum length, except in MFMA-FJ Third Grade Northern Hard Maple flooring, where 4" minimum length shall be allowed.
Segment Length Guidelines
Segment length requirements are based on average number of segments per lineal foot of flooring. Segment count shall always include end segments. Maximum number of segments in MFMA-FJ flooring is .65 segments per lineal foot of flooring averaged over 5,000 lineal feet (average pallet size) of flooring.
Example: The permitted number of segments in 5,000 lineal feet of flooring shall be .65 x 5,000 or 3,250 segments.
In MFMA-FJ Third and Better Northern Hard Maple and MFMA-FJ Third Grade Northern Hard Maple, the maximum number of segments is .80 segments per lineal foot of flooring averaged over 5,000 lineal feet of flooring.
HOW TO SPECIFY MFMA-FJ (Finger Jointed) NORTHERN HARD MAPLE FLOORING
MFMA-FJ (Finger Jointed) strip flooring is specified in the same manner as MFMA-RL (Random Length) and MFMA-PQ (Parquet) Northern Hard Maple flooring. For example, when ordering, requesting or specifying MFMA-FJ (Finger Jointed) strip flooring, specify as "MFMA-FJ" and list the grade, required species, and thickness. A typical specification should appear as follows:
A. Flooring shall be MFMA-FJ First Grade Northern Hard Maple, 25/32" thick x 2-1/4" wide; T & G and EM; grade marked and stamped as produced by an MFMA member manufacturer.
MFMA-FJ (Finger Jointed) NORTHERN HARD MAPLE FLOORING GRADING RULES
MFMA - FJ (Finger Jointed) First Grade Northern Hard Maple
The highest standard MFMA grade is hand selected to minimize the natural character variations of the species.
This grade of MFMA-FJ Northern Hard Maple combines appearance and durability and has a face free of defects that will materially mar the appearance of the finished floor or impair its durability. A practical application of this rule will admit variations in the natural color of the wood; an occasional small, firm pin knot not over 1/8" in diameter, provided it does not occur on edges or ends of strips; occasional dark green or black spots or streaks not over 1/4" wide and 3" long (or its equivalent) which may contain a slight check not over 1/2" long, providing it is boxed within the piece; bird's-eyes and small burls; a slightly torn grain; or similar defect which can be readily removed by the ordinary method of smoothing the floor when it is laid.
Bark streaks shall not be permitted. A slightly shallow place not over 12" long on the underside of flooring, if it does not extend to either end of the piece, and an otherwise perfect tongue which is one-half short for 25 percent of length of piece, are admissible, but the face must be free of shake, and the wood must be live and sound.
MFMA-FJ (Finger Jointed) Second and Better Grade Northern Hard Maple
The most commonly specified flooring, this grade exhibits more natural variations than first grade.
This grade admits tight, sound knots, provided they do not occur on edges or ends of strips; distinct color variations; numerous dark green or black spots or streaks - provided they do not occur in combination with predominately dark heartwood; slight checks not exceeding 3" in length and running parallel with and well inside the edges and ends of the strip; dark spots or streaks with slight checks in center; small rough spots which cannot be wholly removed by the ordinary method of smoothing the floor when it is laid; slightly torn edges; short tongue if sufficient to hold properly in the floor; shallow or waney back if piece has sufficient bearings of full thickness to support it in the floor; and slight variation in angle of end matching. With the use of some finishes, light sticker shadow and color variations may appear. While these and similar features are admissible, sufficient attention is given to appearance to make this grade desirable and satisfactory for use in stores, schools, factories, and similar places where superficial defects and blemishes are not a real factor of consideration. The face must be free of shake, and the wood must be live and sound. Bark streaks shall not be permitted.
MFMA-FJ (Finger Jointed) Third and Better Grade Northern Hard Maple
This grade of MFMA-FJ maple is comprised of a mixture of all other grades of MFMA-FJ Northern Hard Maple. The lowest grade admissible shall not be less than MFMA-FJ Third Grade Northern Hard Maple. MFMA-FJ Third and Better Northern Hard Maple is suited for nearly any application where variations in appearance are not an aesthetic concern. This grade can be produced as a mill run product provided it contains a minimum of 60 percent MFMA-FJ Second and Better Northern Hard Maple; however it can also be produced by mixing 60 percent MFMA-FJ Second and Better Northern Hard Maple and 40 percent MFMA-FJ Third Grade Northern Hard Maple. This grade allows defects as described in other grades of MFMA-FJ Northern Hard Maple flooring.
MFMA-FJ (Finger Jointed) Third Grade Northern Hard Maple
This grade has the same structural integrity as first and second and better and exhibits more natural variation than either grade. This grade is ideally suited for the value engineered application.
This grade may contain all defects common to maple, but the wood must be firm and serviceable. It will not admit voids on edges or ends, or knot holes over 3/8" in diameter; partially unsound knots where the unsound portion is over 1" in diameter; or shakes, heart checks, badly split ends and imperfections in manufacture which materially impair the serviceability of the flooring for the purpose intended.
MFMA-FJ (Finger Jointed) Utility Grade Northern Hard Maple
This grade of MFMA-FJ maple may contain all defects common to maple, but the wood must be firm and serviceable. MFMA-FJ Utility Grade Northern Hard Maple will not admit voids on edges or ends, or knot holes over 3/8" in diameter; partially unsound knots where the unsound portion is over 1" in diameter; or shakes, heart checks, badly split ends and imperfections in manufacture which materially impair the serviceability of the flooring for the purpose intended. Individual segments in this grade have no minimum length requirements.
RULES GOVERNING REINSPECTION
Even the most experienced inspectors will occasionally misgrade some pieces. Therefore:
Shipments shall be considered to be the grade invoiced if, upon inspection by an official inspector of the Maple Flooring Manufacturers Association, 95 percent or more, in feet, is found to be of grade invoiced. Where the degrades are in excess of 5 percent, in feet, of the shipment, the degrades in excess of the 5 percent shall be the property of the manufacturer of the flooring.
The quality of the flooring in the condition in which it leaves the manufacturer is held to govern the grade, as subsequent lack of care and improper treatment in laying, sanding or finishing are not chargeable to the manufacturer.
In the event that the amount below grade is found to be 5 percent or less, in feet, of the total amount of the item, the cost of reinspection shall be borne by the complainant. If more than 5 percent in feet, the expense shall be borne by the manufacturer of the flooring.
For dispute resolution contact MFMA. Specific "Guidelines for Reinspection" are available upon request. In any dispute involving the grade of the flooring material where an MFMA reinspection is requested, the determination of the MFMA inspector shall prevail.
SIZES OF MFMA-FJ (Finger Jointed) NORTHERN HARD MAPLE FLOORING
| Tongued and
|| 13 mm
|| 20 mm
CARE OF FLOORING AFTER DELIVERY
MFMA-FJ (Finger Jointed) Northern Hard Maple flooring is made from lumber kiln-dried to the proper moisture content. After kiln drying, the lumber is air-cooled and cut into strips, accurately milled, carefully graded, bundled, and stored in a dry, well-ventilated warehouse.
As a valuable product, it deserves from the dealer, trucker, and floor layer the same care in handling accorded by the manufacturer. TO ENSURE the most satisfactory results in the finished floor, observe these simple precautions:
- Don't unload, truck or transfer flooring in rain or snow. If atmosphere is foggy or damp, cover with a tarpaulin.
- Don't store flooring in leaking or open enclosures.
- Don't unload flooring outside of a shelter at the jobsite.
- Don't overlook providing protected ventilation to keep relative humidity at a minimum.
- Don't store or lay flooring in a cold, damp building or directly on a concrete slab. Wait until plastering and cement work are thoroughly dried and woodwork and trim are installed.
Flooring should be delivered to the premises a minimum of seven days prior to installation, or as required for proper acclimation. All flooring shall be placed in the area into which it is to be installed to assure proper acclimation to the environmental conditions of the facility.
The Maple Flooring Manufacturers Association has produced a library of technical information designed for specifiers, architects, end users and other professionals. Below is a complete list of available publications and videos:
Caring for your MFMA Maple Floor (Wall Chart)
Floor Finish List & Specifications
Incidence of Injury Study: Maple Flooring vs. Synthetic
Life Cycle Cost Study Summary and Cost Comparison Worksheet
Maple Flooring: Today's Preferred Sports Surface
MFMA Guide Specifications (for subfloor systems)
MFMA Maple Flooring: The Logical Choice for Your Home
Performance Characteristics Guide
Sanding, Sealing, Court Lining, Finishing and Resurfacing
"Playing For Keeps" - A bilingual (English and Spanish) training guide for proper care and maintenance of MFMA maple sports floors (9:49 min).
Available in DVD or VHS.
"Your Next Sports Floor, Things You Should Know" - Owners and end-users talk about MFMA maple sports floors (12:04 min).
Available in VHS only.
"Putting It All Together: Installation Procedures and Guidelines" - A training guide for installation of MFMA sports floors (14:20 min).
Available in DVD or VHS.
The Maple Flooring Manufacturers Association (MFMA) provides these Finger Jointed Flooring Grading Rules, including proposals on care, as a guide to specifiers, architects, end users, and other professionals. MFMA, its members and employees do not warrant the information contained herein as proper under all conditions. MFMA reserves the right to revise these Finger Jointed Flooring Grading Rules as necessary.
Maple Flooring Manufacturers Association
111 Deer Lake Road, Suite 100
Revised March 2008