United States Department of Agriculture Wood Particleboard Forest Service Forest and Flakeboard Products Laboratory General Technical Types, Grades, and Uses Report FPL-GTR-53 Abstract Contents This report is for those who use or Page may want to use wood particleboard. The term “particleboard” is used as Particleboard–What IS it? . 1 defined in the American Society for Testing and Materials (ASTM) Standards for Particleboard . 1 Standard D 1554, which includes flakeboards as a subclass of Particleboard Applications . 2 particleboards, and not as used in the lumber trade where the term is usually Underlayment ............... 2 reserved for panels made of fine wood particles such as sawdust and planer Stair Tread and Shelving ...... 4 shavings. Types and grades of particleboard are described and Grades for Industrial Uses .... 4 discussed in relation to end uses as nonstructural underlayment, stair Subflooring and Combination tread, shelving, furniture, core Subfloor/Underlayment ..... 5 material, cabinetry, structural sheathing, subflooring and Wall and Roof Sheathing. ..... 7 combination subfloor/underlayment, and siding. The structural panels used Siding ..................... 7 in light-frame construction are primarily flakeboards. Formaldehyde Emissions ....... 8 Keywords: End uses, particleboard, Glossary ..................... 8 flakeboard, waferboard, strandboard, composite plywood, underlayment, References ................... 9 stair tread, shelving, furniture, sheathing, siding, mobile home, building codes, standards. November 1986 Carll, Charles. Wood particleboard and flakeboard: Types, grades, and uses. Gen. Tech. Rep. FPL-GTR-53. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory; 1986. 9 p. A limited number of free copies of this publication are available to the public from the Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53705-2398. Laboratory publications are sent to over 1,000 libraries in the United States and elsewhere. The Laboratory is maintained in cooperation with the University of Wisconsin. Wood Particleboard and Flakeboard Types, Grades, and Uses Charles Carll, Research Forest Products Technologist Forest Products Laboratory, Madison, WI Particleboard— Standards for What Is It? Particleboard Wood particleboards are Particleboard panels are currently Tables 1 and 2, reproduced from manufactured as panels from dry available for many end uses. All but ANSI Standard A208.1, state property wood particles that have been one (oriented strandboard) of the requirements for the panel grades sprayed or dusted (speckled) with a particleboards commercially available addressed in this standard. The binder resin, and are bonded together are addressed in the American Standard recognizes panel types 1 with pressure and heat. Particles for National Standard, ANSI A208.1 for and 2, indicated by the first number in the boards can be made from almost mat-formed wood particleboard. the grade designation. Type 1 panels any type of wood, whether whole logs Developed under the auspices of the (table 1) are manufactured with an or wood residues such as trimmings American National Standards Institute, adhesive (or binder resin) which has and shavings from lumber or plywood ANSI A208.1 is a voluntary product some water resistance but is not manufacturing. Many species are standard, which means that producers waterproof, usually urea-formaldehyde used, although the lower density are not restricted to the manufacture binder resin. Type 2 panels (table 2), woods are preferred. In this paper, the of particleboards conforming to the including waferboard (2-MW) and term “particleboard” includes a standard. Conformance to the flakeboard (2-MF), are manufactured number of different panel types standard is required only when boards with a waterproof binder resin, usually sometimes referred to variously offered for sale are represented as phenol-formaldehyde. Use of a as “chipboard,” “flakeboard,” conforming to the standard, or when a phenolic binder resin does not “strandboard,” or “waferboard,” customer requests a certain grade necessarily result in a particleboard depending on size and shape of the from the standard, or when required panel suitable for permanent exterior wood particles used. (See Glossary by a design specification or regulation. exposure, just as use of phenolic from ASTM D 1554 below.) The ANSI Standard A208.1 waterproof adhesive in sheathing Almost all particleboard is produced specifies dimensional tolerances of plywood does not result in a plywood by pressing a mat of resin-speckled panels and required minimal levels of panel intended for permanent exterior particles flatwise in a heated press. physical and mechanical properties for exposure. Extruded boards produced by forcing various grades of particleboard. Within the two panel types the resin-speckled particles between recognized in ANSI Standard 208.1, parallel heated dies represent a the grade specification indicates miniscule proportion of the density classes by the letters H (high), particleboard produced. M (medium), and L (low). With wood at 7 percent moisture content, these classes approximate density values of over 50 pounds per cubic foot (lb/ft3) (H), 40 to 50 lb/ft3 (M), and less than 40 lb/ft3 (L). Particleboard Applications The strength-stiffness requirements Specific uses of board products are Underlayment particleboard is for different grades listed in tables 1 discussed in the following sections. nonstructural and has no code and 2 are not intended to be used as For any of these uses it is advisable approval for use as subflooring or design values for construction. The to purchase panels produced under a single-layer subflooring/underlayment. property values listed in the tables are certified quality program, where Figure 1 shows a specimen of for grade certification and quality established grade marks on the panel underlayment-grade particleboard. control where test conditions and identify the use, grade, or quality of Waferboard (discussed in subsequent methods are precisely controlled and the panel, and the mill at which it paragraphs) is sometimes used as follow provisions outlined in the was manufactured. Six different underlayment, particularly under American Society for Testing and organizations administer certified carpeting. Materials (ASTM) Standard D 1037. quality programs for particleboard or In-service conditions may differ from particleboard-veneer composites those specified in this standard. The manufactured in the United States and strength and stiffness values listed in Canada. These organizations are tables 1 and 2 are several times the listed in the reference section. design values that would be appropriate for use of these materials Underlayment in engineered applications. At the date of this writing, revision Particleboards of grade 1-M-1, ANSI of ANSI A208.1 is expected to result A208.1, are manufactured for floor in separate standards for fine furnish underlayment where they particleboards and for flakeboards. provide a smooth, level, and The American Plywood Association indentation-resistant surface for the (APA) and Timber Engineering subsequent application of carpeting or Company (TECO) have published resilient-finish floors such as linoleum, performance standards for sheathing vinyl, or vinyl-asbestos tile. and for combination subfloor and underlayment. The Council of American Building Officials Research Board, which is sponsored jointly by the three model building codes (see reference section), has recognized these APA and TECO performance standards. Certain particleboard panels (most notably a number of flakeboard products) meet these performance standards and thus have model-building-code recognition for use as sheathing or combination subfloor and underlayment. In fact, most of the flakeboard panels marketed for these uses bear gradestamps showing conformance to the APA or TECO performance standards. The model building codes, their authors, and addresses are listed in the reference section of this publication. Figure 1—Specimen of underlayment particleboard. (Numbered scale in inches.) (M 150 064) 2 Table 1.—Property requirements for grades of type 1 mat-formed particleboarda (Average values for sample consisting of 5 panels)b Thickness Length Modulus Modulus Linear Screwholding tolerance Internal Grade and of of Hardness expansion width bond maximum Panel Within rupture elasticity Face Edge tolerance averaged panele average 2 --------------- in --------------- ---------------Lb/in. --------------- Lb Pct ------ Lb------ 1-H-1 ±1/16 ±0.010 ±0.005 2,400 350,000 130 500 NSc 400 300 1-H-2 ±1/16 ±0.010 ±0.005 3,000 350,000 130 1,000 NS 425 350 1-H-3 ±1/16 ±0.010 ±0.005 3,400 400,000 140 1,500 NS 450 350 1-M-1 +0 -1/8 +0.015 ±0.010 1,600 250,000 60 500 0.35 NS NS 1-M-2 ±1/16 ±0.010 ±0.005 2,100 325,000 60 500 0.35 225 200 1-M-3 ±1/16 ±0.010 ±0.005 2,400 400,000 80 500 0.35 250 225 1-L-1 ±1/16 +0.005 ±0.005 800 150,000 20 NS 0.30 125 NS -0.015 aMade with urea-formaldehyde resin binders or equivalent bonding systems. bExcept for dimensional tolerances which are individual panel values. cNS–not specified. dPanel average from nominal. elndividual measurement from panel average. Table 2.—Property requirements for grades of type 2 mat-formed particleboarda (Average values for sample consisting of 5 panels)b Thicknesse Length Modulus Modulus Linear Screwholding tolerance Internal Grade and of of Hardness expansion width Panel Within rupture elasticity bond maximum h Face Edge tolerance averages panel average 2 ---------------- in ---------------- ---------------- Lb/in, ---------------- Lb Pct ------Lb ------ 2-H-1 ±1/16 ±0.015 ±0.005 2,400 350,000 125 500 NSd 400 300 2-H-2 ±1/16 ±0.015 ±0.005 3,400 400,000 300 1,800 NS 450 350 2-M-1 +0 -1/8 ±0.015 ±0.010 1,800 250,000 60 500 0.35 225 160 2-M-2 +0 -1/8 ±0.015 ±0.010 2,500 450,000 60 500 0.35 250 200 2-M-3 +0 -1/8 ±0.015 ±0.010 3,000 500,000 60 500 0.35 NS NS c 2-MW +0 -1/8 ±0.015 ±0.010 2,500 450,000 50 500 0.20 NS NS f 2-MF +0 -1/8 ±0.015 ±0.010 3,000 500,000 50 500 0.20 NS NS aMade with phenol-formaldehyde resins or equivalent bonding systems.