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Section 5
5.9.0 Thermal Resistance of Wood Structural Panels
(By permission from APA—The Engineered Wood Association, Tacoma, Washington.)
Plywood, Composite Wood Products, High-Pressure Laminates
5.9.1 Average “U” Values of APA Panel Roof Decks
(By permission from APA—The Engineered Wood Association, Tacoma, Washington.)
5.9.2 STC 46 Party Wall Construction
(By permission from APA—The Engineered Wood Association, Tacoma, Washington.)
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5.10.0 APA-Rated Sturdi-Floor Subfloor and Floor Framing for Hardwood Floors
(By permission from APA—The Engineered Wood Association, Tacoma, Washington.)
5.11.0 Composite Wood Products Along with lumber and plywood, within the past 40 years, a new wood product has gained wide acceptance in the industry, composite wood products. These products are panels and laminated materials made up of small pieces of wood glued together, oftentimes with plastic fillers. These products are frequently referred to as engineered wood products. 5.11.1 Hardboard (Compressed Fiberboard) A board manufactured from interfelted lignocellulosis fibers, consolidated under heat and pressure to form a dense material. • Available thicknesses Typically 1⁄8" (12.7 mm) to 1⁄2" (38.1 mm). • Density 45 to 70 pounds/cubic foot (705 to 112 kg/cubic meter). • Uses Exterior siding, peg board, decorative wall paneling, underlayment, drawer bottoms, furniture backs, and simulated wood shingles and shakes. 5.11.2 Cellulosic Fiberboard (Softboard) Made from wood fibers, recycled paper, bagasse (a plant residue, such as from sugar cane), and other agricultural by-products • Available thicknesses Typically 1⁄2" (12.7 mm) to 2" (50.8 mm). • Density Typically 10 to 25 pounds/cubic foot (160 to 400 kg/cubic meter). • Uses
Wall sheathing, roof insulation, and sound insulation.
Plywood, Composite Wood Products, High-Pressure Laminates
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5.11.3 Oriented Strand Board (OSB) This material evolved from waferboard and is constructed of strands of softwood or hardwood 1⁄2" (12.7 mm) wide by 3" (76.2 mm) to 4'6" (1.37 m) in length. • Available thicknesses Typically 1⁄4" (6.4 mm) to 11⁄8" (28.6 mm). • Density 36 to 44 pounds/cubic foot (577 to 705 kg/cubic meter). • Uses Interchangeably used in structural applications in the same way as plywood. Phenolic paper overlaid OSB is used for siding. 5.11.4 Waferboard Similar to OSB, except that it is composed of large flakes of wood bonded together and generally made from low-density hardwoods, such as aspen. Once used a great deal as sheathing, it has largely been replaced by OSB. 5.11.5 Laminated Veneer Lumber (LVL) Primarily a structural member made of veneer laid up in one grain direction and made in billets 27" (68.6 cm) to 50" (127 cm) wide and 11⁄2" (38.1 mm) or 13⁄4" (44.5 mm) thick. Produced under pressure to cure the adhesives, mostly phenolic glues. This material is nondestructively tested to ensure consistent strength. TrusJoist MacMillan uses this material as flanges in their I-joists. 5.11.6 Parallel-Strand Lumber (PSL) These products are made of oriented strands of waste softwood veneer. The 1⁄2" (12.7 mm) wide by 37" (94 cm) long strands are oriented and laid up into a mat, which is processed through a microwave-heating system into billets of 11" (279 mm) 18" (457 mm) or 11" (279 mm) 14" (355 mm). These billets are sawn into lengths and thicknesses, as required. PSL members are used where high-strength lumber or timber materials are required. TrusJoist MacMillan’s Parallam is a PSL product. 5.11.7 Oriented Strand Lumber (OSL) OSL is made with nominal 12" (300 mm) long strands and pressed in a steam-injection press machine to produce uniform density throughout. This material, developed by McMillan Bloedel, Ltd., is also used in joist construction. 5.11.8 Com-Ply Com-Ply is a material developed by the USDA Forest Service in the 1970s and composed of random or oriented wood flakes or particles sandwiched between two layers of veneer. One or more layers of veneer are also placed on the faces or edges of the lumber. This material is not widely used today. 5.12.0 Medium-Density Fiberboard (MDF) Dry-formed panels manufactured from lignocellulosis fibers, combined with a synthetic resin or other suitable binder. • Available thicknesses order).
3
⁄16" (4.74 mm) to 11⁄2" (38.1 mm) (3", 76.2 mm, is available on special
• Density 40 to 50 pounds/cubic foot (641 to 801 kg/cubic meter). • Uses
Moldings or millwork where it replaces solid wood.
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5.12.1 MDF Product Certifications and Uses
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
Plywood, Composite Wood Products, High-Pressure Laminates
5.12.2 MDF Raw Material Composition
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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5.12.3 MDF Wood and Vinyl Veneers and Dimensional Characteristics
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
Plywood, Composite Wood Products, High-Pressure Laminates
5.12.4 Dimensional Stability as a Critical Factor
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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5.12.5 Particleboard and MDF Grades and Property Requirements
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
Plywood, Composite Wood Products, High-Pressure Laminates
5.12.6 Effect of Moisture on Cross Lamination of Veneered Lumber Products
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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5.12.7 Moisture Content of Particleboard and the Impact on Warpage When used as a substrate for plastic laminate facings, these particleboard and fiberboard panels are subject to warpage if not stored properly. Warpage can also occur when an unbalanced laminated panel is produced—one with a face sheet of high-pressure laminate, but no backer sheet. Moisture content building up in the unfaced panel causes stresses to accumulate. When these stresses become excessive and are no longer equally balanced, cracks can occur in the laminate. This unbalance can occur because of a number of factors: • Selection of laminate other than HPL, such as a wood veneer. • The environment in which laminating is to occur. • Conditioning (or lack thereof) of each component of the assembly. • Product design problems. • Installation procedures Unusually moist or dry conditions should be avoided in both the storage of the substrate and the laminating environment.
5.12.8 Moisture Content Zones in the U.S.
(Reprinted with the permission of National Particleboard Association, Gaithersburg, Maryland.)
Plywood, Composite Wood Products, High-Pressure Laminates
5.12.9 Particleboard and MDF Dimensional Changes Compared to Wood
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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5.12.10 Dimensional Changes in Medium-Density Fiberboard (MDF) and Industrial-Grade Particle Board (PBI)
(Reprinted with the permission of National Particleboard Association, Gaithersburg, Maryland.)
Plywood, Composite Wood Products, High-Pressure Laminates
5.12.11 Ideal Fabrication Conditions Chart
(Reprinted with the permission of National Particleboard Association, Gaithersburg, Maryland.)
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5.12.12 Selected Substrates—Handling and Storage Suggestions
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
Plywood, Composite Wood Products, High-Pressure Laminates
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5.12.13 Use of Particleboard as Underlayment
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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Section 5
Continued
Plywood, Composite Wood Products, High-Pressure Laminates
Continued
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5.12.14 Placement of Various Types of Flooring Over Particleboard Underlayment
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
Plywood, Composite Wood Products, High-Pressure Laminates
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5.12.15 Particleboard as Stepping
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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Section 5
Continued
Plywood, Composite Wood Products, High-Pressure Laminates
5.12.16 MDF Moldings and Millwork
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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Continued
Plywood, Composite Wood Products, High-Pressure Laminates
5.12.17 Saw/Cutting, Installing MDF Moldings, and Millwork
(Reprinted with the permission of the Composite Panel Assoc., 18928 Premiere Court, Gaithersburg, Maryland.)
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