Veneer Panel Products
Plywood is made by gluing plies of veneer together at right angles; the product comes in 3 plies, 4 plies or 5 plies (the more plies in a sheet, the stronger the plywood.) It is available in special order widths and lengths as well as standard 4' x 8' (1.2m x 2.4m) sheets with nominal thicknesses from 1/8" (3mm) to 1-1/8" (28mm).
Plywood is divided into two basic categories: exterior and interior. Exterior plywood (or appearance-grade plywood) is made with water-resistant glue, and its outer veneers are made from water-resistant wood making it ideal for siding or panelling. Interior plywood (or engineered-grade plywood) is also made with water-resistant glue, but its veneers do not weather well. Interior plywood is perfect for concrete forms, sheathing and subfloors. All plywood should be sealed and painted before exposure to weather and water.
Types of Plywood
Hardwood plywood is manufactured for interior finish uses such as cabinets, doors and furniture, and graded on both front and back veneers. With cores made of particleboard, fibreboard, or a combination of the two, hardwood plywood is quite durable. Common species include birch, oak and maple.
Unsanded softwood plywood is primarily used for structural applications such as roofs, walls and floors due to its strength and durability. Sanded softwood plywood is used mainly in concrete formwork and non-structural applications. Common species include pine and fir.
Wood panel products are graded according to their intended use, therefore only its appearance and structural properties are judged for adequacy.
- A = Cabinet Grade
- B = Sanded Grade
- C or C plugged = Sheathing Grade
"A" veneer on face, "B" veneer on back
- Applications where a smooth paintable surface is needed
"A" veneer on face, "C" veneer on back
- Applications where one smooth side is needed
"B" veneer on face, "C" veneer on back
- Applications where a reasonable painted surface is required and economy is a major consideration
"C" veneer, filled and touch sanded on face, "C plugged" veneer on back
- Applications where appearance is not important
Veneer Cutting Methods
Plain Slicing (Flat Slicing)
Plain slicing is the most common method of veneer cutting and produces a consistent cathedral grain pattern. Consecutive leaves of veneer are cut with the blade parallel to the length of the log.
In rotary slicing, an entire log is mounted on a lathe and peeled to yield continuous sheets of veneer. Rotary cutting creates broad grain patterns which are rarely duplicated. It is the most economical cutting method.
Quarter slicing produces a very straight grain pattern. The cutting blade is perpendicular to the growth rings and quartered leaves are sliced consecutively. A flake pattern may occur in species such as oak due to the radial patterns being bisected.
In rift slicing, the angle of the blade can be varied to produce veneer with a straight and narrow grain pattern. Rift grain is easily sequenced and matched.
Reconstituted Panel Products
Types of Boards
Oriented Strand Board (OSB)
Oriented Strand Board (OSB) structural panels are manufactured using wood strands and waterproof adhesives. The wood strands are arranged in cross-oriented layers to provide strength and performance properties similar to plywood. OSB has a consistent quality with no gaps or voids. Common uses of OSB in residential construction include: subflooring, roof sheathing, wall sheathing, ceilings and soffits. OSB is manufactured with either a square edge or tongue-and-groove edge, and the thicknesses range from 1/4" (6mm) to 3/4" (18.5mm).
Particleboard is made of wood particles (approximately sawdust size) bonded with resins and formed into panels under heat and pressure. These panels are used primarily for floor underlayment and in manufacturing cabinets, laminate countertops and doors. Particleboard makes better underlayment than plywood because there are no voids in the core that might dent under resilient flooring, and it also makes a good base for countertop laminates because of its smoothness and stability. However, particleboard has little structural strength, and a tendency to swell and disintegrate when it gets wet.
Thicknesses range from 1/4" (6mm) to 1-1/8" (27mm), and common sizes are 4' (1.2m) wide and 8' (2.4m) to 12' (3.6m) long.
Melamine is a thermally coated high-performance particleboard that is scratch and fire resistant and available in 49" x 97" (1.2m x 2.4m) sheets. This versatile panel product is a popular material for kitchen cabinetry interiors and laundry room shelving as it is inexpensive and easy to clean.
Medium-Density Fibreboard (MDF)
Medium-Density Fibreboard (MDF) is made by compressing recovered and recycled wood fibre to form an engineered wood product, and costs a fraction of the price of solid wood. Standard MDF is ideal for building countertops, doors, furniture, cabinets and shelving. Moisture-resistant MDF is recommended for interior applications where there is the risk of occasional wetting or prolonged exposure to high levels of humidity.
Lighter density fibreboards are also available: ultralight-density and light-density. Both are designed for use in situations where the weight of a standard MDF is a factor. Ultralight-density fibreboard is 30% lighter than standard MDF and is commonly used for award plaques, picture frames, table tops, mobile homes and mouldings. Light-density fibreboard is 20% lighter than standard MDF and is ideal for many of the same applications as standard MDF.
Similar to MDF, hardboard is constructed of wood fibres and softwood pulp, and considered to be fibreboard. The primary difference between MDF and hardboard lies in the density of the panel and the additives that make them specially suited for different applications.
Medium-density hardboard is typically 3/8" (10mm) and 7/16" (11mm) thick, and manufactured as preprimed or prefinished panel, lap siding or roofing shingles. It is also used for doors, soffits and other applications where it can be protected from moisture and weather. High-density hardboard is typically 1/8" (3mm) and 1/4" (6mm) thick, and used for curved forms.
Perforated hardboard also referred to as pegboard is tempered, making it resistant to moisture. Pegboard is typically 1/4" (6mm) thick and commonly used on walls in garages and workshops for organization and storage.