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. bExcept for dimensional tolerances which are individual panel values. c“W” indicates that this product is made from wafers. dNS—not specified. eThickness tolerance values shown are for sanded panels as defined by the manufacturer. Values for unsanded panels for all 2-M Grades shall be ±0.030 for panel average and ±0.030 for within panel. f“F” indicates that this product is made from flakes. gPanel average from nominal. hlndividual measurement from panel average. Particleboard underlayment is Some urea-bonded fine-furnish Another grade of urea- attached to lumber or plywood particleboard is sold as shelving. formaldehyde-bonded particleboard subflooring with ring-grooved Some shelving is marketed as plain is mobile home floor decking. This underlayment nails or galvanized board (usually with a nosed front board serves as a single-layer or divergent-chisel-point power-driven edge), and some is sold overlaid with combination subfloor and staples. Glue-nailing with hard-setting high-pressure laminate (as used on underlayment in mobile home casein glue or polyvinyl acetate floor countertops) or with veneer. Overlaid construction. In this application, the underlayment glue provides superior panels are stronger, stiffer, and more board is installed atop wood floor attachment. The reader is referred to resistant to sagging. The National joists which, in turn, are attached to the booklet “How to Install Particleboard Association has the mobile home’s metal chassis. The Particleboard Floor Underlayment” published guides for particleboard board is usually glue-nailed to the published by the National shelving design. These guides mobile home floor joists with Particleboard Association. This indicate how to arrange shelf supports power-driven ring-grooved nails and instruction guide was written before or choose particleboard grade and polyvinyl acetate (“white”) glue. The flakeboards came into use as thickness to support given loads. Their industry standard for this special use structural subfloor and hence does not usefulness depends on your knowing panel, NPA 1-73, states that the board mention how to attach underlayment the particleboard grade (or more must pass a concentrated load test particleboard to a flakeboard subfloor. specifically its bending strength described therein. With the exception However, the application would be the and stiffness). Unfortunately, a of interior stair tread, mobile home same as to lumber or plywood considerable quantity of particleboard floor deck is the only structural subfloor. In new construction, shelving is sold without any indication application where a urea-bonded single-layer subfloor/underlayment is of its grade (1-M-1, 1-M-2, or 1-M-3) panel is permitted in North America. often used, eliminating the need for or its bending strength and stiffness. It The rationale for this is (1) that a attachment of underlayment to is obviously prudent to assume that mobile home is manufactured indoors subflooring. unidentified boards have bending and so there is no opportunity for its properties no greater than those of floor deck to be exposed to rain Stair Tread and grade 1-M-1 panels. Simple rules of during construction and (2) that the Shelving thumb are to keep shelf supports expected service life is shorter for a close together (this will likely be mobile home than a house. At least Some urea-bonded fine-furnish determined by wall stud spacing) and two particleboard manufacturers are particleboard is produced for use where possible to support the rear now making mobile home floor deck as interior stair tread. The U.S. edge of the shelf. with waterproof isocyanate adhesive. Department of Housing and Urban Particleboard panels of grade 2-M-2 Development (HUD) has published a Grades for of ANSI A208.1 are manufactured Use of Materials Bulletin (UM 70a) for Industrial Uses primarily for use as single-layer particleboard interior stair treads. The combination subfloor and International Conference of Building Grades 1-M-2 and 1-M-3 of ANSI underlayment in factory-built housing. Officials (ICBO) has also issued a A208.1 are manufactured for Boards intended for this use must research report (RR 3390) on the use industrial furniture manufacturers that pass a concentrated load test. The of particleboard stair treads. Both consume large quantities board is similar to mobile home HUD and ICBO require gradestamping of urea-formaldehyde-bonded decking, but has a type 2 bond to indicate that particleboard stair particleboard. The particleboard is because of the stricter requirements treads conform to the material usually overlaid in furniture with for factory-built housing. Glue-nailing, requirements. The HUD and ICBO veneer, plastic, vinyl, printer foil, with ring-grooved nails and publications also specify minimum transfer films, or high-pressure elastomeric construction adhesive, is tread thickness of 1-1/16 inches, laminate as in kitchen countertops. the approved method of attaching maximum tread width of 11-1/8 or Some particleboard manufacturers particleboard floor deck to floor joists 12 inches, maximum span between may produce panels bonded with of factory-built housing. support stringers of 42 inches, and isocyanate (urethane) for industrial require that all particleboard treads be furniture manufacturers. The supported by risers with nails through isocyanate adhesive does not release the riser into the back of the lower formaldehyde vapors and is tread, and have a nosed (rounded) waterproof. Grade 1-L-1 panels are edge and waterproof protection for manufactured as core material for treads located near entryways (hence fabricators of solid doors. Solid doors subject to wet foot traffic). The are used primarily in public buildings National Particleboard Association has or where there are requirements for published a bulletin concerning fire endurance of doors. installation of particleboard stair tread.

4 Subflooring and Combination Subfloor/Underlayment

As floor sheathing, structural panels are subject to bending stress and concentrated static and impact loads. In addition, they provide racking resistance to the floor. Panels in this application must provide racking resistance and must not deflect excessively under load nor fail in bending or punching shear. The requirements for combination subfloor/underlayment are similar, but more stringent. Various structural particleboards, most of them flakeboards, are recognized by the model building codes for use as Figure 2—specimen of waferboard. Note the wide wafers, subfloor or subfloor/underlayment. (Numbered scale in inches.) (M 150 065) Panels that conform to grade 2-M-3 of ANSI A208.1 have obtained model code recognition for use as combination subfloor and Grade 2-MW of ANSI A208.1 is Oriented strandboard (OSB) is underlayment. Grade 2-M-3 panels waferboard. This panel grade is constructed of wood flakes or strands are made of a fairly fine particle recognized by the model codes for that are similar to wafers but furnish with a generous amount of use as sheathing or combination narrower. Being narrower, the strands phenolic adhesive and are denser subfloor/underlayment (subject, of can be aligned. OSB is made of than most medium-density course, to requirements set out in the strands aligned (oriented) in layers particleboards. For use as codes for panel thickness, and that run perpendicular to each other combination subfloor/underlayment attachment and spacing of framing (fig. 3) as in the cross-laminated 2-M-3 panels must have tongue and members). Waferboard is classified as construction of plywood. Flake groove edges or their edges must be a flakeboard, and figure 2 shows a alignment gives the panel superior supported with blocking. Panels specimen of this board type. bending strength and stiffness, but similar in construction to grade 2-M-3 Waferboard panels may also meet only if surface layer orientation runs panels may meet performance performance requirements of APA or perpendicular to the framing requirements of the performance TECO performance standards for members. OSB is most often certified standards for combination sheathing and/or for combination as conforming to the APA or TECO subfloor/underlayment and be subfloor/underlayment (dependent on performance standards for gradestamped as conforming to one thickness) and may obtain code sheathing and/or combination of the performance standards. recognition for use as subfloor or subfloor/underlayment (dependent on Because there are three different subfloor underlayment by this route. thickness). The difference between model-code-writing agencies and OSB and waferboard is not as distinct because the model codes are not as it was in the early 1980’s because static, it is best for potential users of many waferboard producers are now structural panels first to check with cutting wafers with some length-width their local building officials. It should difference and aligning these wafers be noted that local jurisdictions do not to some extent in the panel. always refer to the latest editions of the model codes.

5 Composite plywood panels first became commercially available in 1976. Figure 4 shows a specimen of this panel type comprising a wood particle core sandwiched between veneer faces. As can be seen from the figure, these panels look much like “traditional” softwood plywood. Composite plywood panels are included here because they have a particleboard core. Composite plywood production has not enjoyed the large growth of flakeboard production over the last 5 years, apparently for economic reasons; composite plywood costs more to produce, and plants that produce it are usually farther removed from major markets than competing flakeboard plants. Building-code recognition of composite plywood panels for use as subfloor or combination subfloor/underlayment is given either on a proprietary-product basis or by conformance to performance standards for these end uses. Particleboard subfloor panels are attached to floor joists with deformed shank nails or common nails or cement-coated sinker nails. Particleboard combination subfloor Figure 3—Two small specimens of oriented strandboard. This and underlayment panels are usually shows the board’s three-layer construction and alignment of attached to floor joists with deformed strands in each layer. (Numbered scale in inches.) (M 150 062) shank nails. Glue nailing with elastomeric construction adhesive generally permits wider spacing of nails and provides a more rigid floor. Local building codes should be checked for specific information regarding panel usage and installation. APA, NPA, or TECO also can provide more current and specific information than is contained in this report. Panels approved for structural use in light-frame construction always (or almost always) have face stamps to indicate span rating (maximum allowable distance between support framing members).

Figure 4—Specimen of a composite plywood panel. The edge has been bevel-cut to accentuate the wood-particle core. (Numbered scale in inches.) (M 150 063)

6 Wall and Roof Sheathing

As wall sheathing, structural particleboards generally provide more racking resistance than required. Consequently, panels are usually used that are less expensive (wood fiber) or provide better insulation (foam). Waferboard, OSB, and composite plywood, when applied as wall sheathing, provide a nail base for application of shingle siding. Roof sheathing must take bending stress and provide racking resistance to the roof. As roof sheathing, structural panels must support their own weight and that of roofing materials, snow loads, and persons on the roof and also resist wind and other racking loads. Although the requirements are not as stringent as for subfloor applications, roof sheathing panels must be reasonably strong and stiff in bending and Figure 5—Specimen of grade 2-M-1 board produced for vertical resistant to punching shear failure. exterior siding. This specimen has a textured surface and is overlaid with phenolic-resin impregnated paper. (Numbered scale Waferboard, OSB, and composite in inches.) (M 150 061) plywood are frequently used as roof sheathing and this is the biggest market for these panels. Building code recognition of Waferboard and OSB panels are often The paper overlay provides a uniform, waferboard and OSB for use as wall manufactured with one surface easily paintable surface. Figure 5 and roof sheathing is by conformance roughened or coated with an anti-skid shows a specimen of a paper-overlaid to the ANSI A208.1 grade 2-MW for coating to alleviate this problem. All siding particleboard. Whenever waferboard or to the APA or TECO these panels are attached to framing particleboard is used as exterior performance standard for sheathing. members as construction plywood siding, it is important to prevent panel Building-code recognition of composite would be (i.e. with common nails, or edges from absorbing water. This plywood for these uses may be by more frequently, with cement-coated appears to be particularly important performance standards for sheathing sinker nails). with decay-prone wood species such or by proprietary product. ANSI A208.1 grades 2-M-1, 2-M-2, as aspen. The model building codes Carpenters perceive that and 2-M-3 find little use as wall or roof require that joints between panels be waferboard, OSB, and composite sheathing, being heavier and covered with wood batten strips or plywood feel stiffer underfoot (i.e. hence more difficult to apply than otherwise be made waterproof to the when spanning framing members) waferboard, OSB, or composite satisfaction of the building official. than do equal thicknesses of plywood, plywood. Codes specify the stud spacing and although static concentrated load tests attachment. Depending on stud do not indicate that these products are Siding spacing, particleboard sheets can be stiffer. They provide a more uniform nailed either directly to studs or to nail base for roof shingles than The model building codes recognize approved sheathing. Attachment plywood and deflect less under ANSI A208.1 2-M grades of should be with galvanized siding nails. hammer blow. However, waferboard particleboard for use as exterior and OSB are more subject to siding. Having fairly smooth faces, the punching shear failure than plywood 2-M-1, 2-M-2, and 2-M-3 panels are and their surfaces often slide easily on easy to paint. Grade 2-MW one another (a stack of these panels (waferboard) has rougher surfaces is much more likely to slide off a and is more difficult to paint. Some sloped framed roof than is a stack of siding manufacturers overlay their plywood or composite plywood). panels with resin-impregnated paper.

7 Formaldehyde Emissions Glossary

Over the past decade considerable The particleboard industry has The terms below are taken verbatim publicity has arisen about reportedly achieved an 80 percent from American Society for Testing and formaldehyde vapor contaminating air reduction of formaldehyde emissions Materials (ASTM) D 1554, standard in dwellings. This contamination can between 1980 and 1985. Resin definitions of terms relating to come from many sources, including manufacturers have decreased the wood-base fiber and particle panel tobacco smoke, urea-formaldehyde ratio of formaldehyde to urea in materials. This standard is also an foam insulation, carpeting, softgoods urea-formaldehyde resins. This American National Standard. furnishings, and particleboard and reduces the “free formaldehyde” Particleboard—A generic term for decorative plywood. release from newly manufactured a panel manufactured from Particleboards bonded with boards, but sometimes at the expense lignocellulosic materials (usually urea-formaldehyde resins emit more of strength and thickness swell. In hot wood) primarily in the form of discrete formaldehyde than do particleboards and damp environments, pieces or particles, as distinguished bonded with phenol-formaldehyde particleboards bonded with from fibers, combined with a synthetic resins. When urea- phenol-formaldehyde or isocyanate resin or other suitable binder and formaldehyde-bonded particleboards should be substituted for bonded together under heat and first emerge from the heated press urea-bonded boards. Research pressure in a hot press by a process where they are produced, they emit continues on reducing fume emissions in which the entire interparticle bond is more formaldehyde vapor than they by adjusting resin formulations or created by the added binder, and to do after aging for a few months but, if adding scavengers. which other materials may have been they are installed in hot and damp Methods to reduce existent air added during manufacture to improve environments, they may continue to contamination in dwellings are (1) to certain properties. Particleboards are emit formaldehyde vapor. The reasons provide more ventilation of dwelling further defined by the method of for this are not fully understood. One spaces and building cavities, where pressing. When the pressure is theory is that hydrolysis of the cured this is possible within acceptable applied in the direction perpendicular urea-formaldehyde occurs in such an energy-loss limits, (2) placing pans of to the faces as in a conventional environment, and results in release of ammonia inside the dwelling as multiplaten hot press, they are defined formaldehyde vapors and loss of formaldehyde scavenger (which as flat-platen pressed and when the board strength. Hydrolysis can requires professional application and applied pressure is parallel to the theoretically continue indefinitely if temporary evacuation of the dwelling, faces, they are defined as extruded. humidity and temperature remain at and, because ammonia is a heart Flake—A small wood particle of high levels. stimulant, may be hazardous to some predetermined dimensions specifically In February 1985, HUD initiated individuals), (3) using air purification produced as a primary function of new product emission standards for equipment, and (4) coating board specialized equipment of various particleboard and hardwood plywood surfaces and edges. types, with the cutting action across used in manufactured homes. The the direction of the grain (either maximum allowable formaldehyde radially, tangentially, or at an angle emission from particleboard is 0.3 part between), the action being such as to per million (ppm) when measured in a produce a particle of uniform large chamber under conditions that thickness, essentially flat, and having simulate a single-width mobile home. the fiber direction essentially in the The National Particleboard plane of the flakes, in overall Association estimates that, since character resembling a small piece of implementation of the Federal rule, veneer. roughly 80 percent of particleboard Particle—The aggregate production conforms to the 0.3 ppm component of a particleboard standard. Each panel from a manufactured by mechanical means production lot that has been certified from wood or other ligno-cellulosic as meeting the standard receives a material (comparable to the aggregate stamp indicating compliance. in concrete) including all small subdivisions of wood such as chips, curls, flakes, sawdust, shavings, slivers, strands, wood flour, and wood wool. Particle size may be measured by the screen mesh that permits passage of the particles and another screen upon which they are retained, or by the measured dimensions as for flakes and strands.

8 References

Administrators of Model Building Codes Certified Quality and Their Administrating Assurance Programs1 Organizations2

American Plywood Association Basic Building Code (BBC) P.O. Box 11700 Administered by the Building Officials Tacoma, WA 98411 and Code Administrators International, Inc. (BOCA) Columbia Research and Testing Corp. 17926 South Halsted Street P.O. Box 968 Homewood, IL 60430 Santa Rosa, CA 95402 Uniform Building Code (UBC) National Particleboard Association Administered by the International 18928 Premiere Court Conference of Building Officials Gaithersburg, MD 20879 (ICBO) 5360 South Workman Mill Road PFS Corporation Whittier, CA 90601 2402 Daniels Street Madison, WI 53704 The Standard Building Code (SBC), Pittsburgh Testing Laboratories formerly the Southern Standard 850 Poplar Street Building Code (SSBC) Pittsburgh, PA 15220 Administered by The Southern Building Code Congress Timber Engineering Company (TECO) International 5530 Wisconsin Avenue, NW. 900 Montclair Road Washington, DC 20015 Birmingham, AL 35213

1The American Plywood Association and National Particleboard Association are industrial trade associations. Timber Engineering Company, Pittsburgh Testing Laboratories, and Columbia Research and Testing Corporation, and PFS Corporation are commercial enterprises.

2These building codes apply to permanent structures only, not to mobile homes. Mandatory Federal standards for mobile home construction U.S. GOVERNMENT PRINTING OFFICE: 1986- 7 2 4 - 0 4 4 / 4 0 0 0 9 were published by the Department of Housing and Urban Development (HUD) in the Federal Register of December 18, 1975, and August 9, 1984. 2 .8-11/86

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