Engineered wood, also called composite wood, man-made wood, or manufactured board; includes a range of derivative wood

Wood

Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 products which are manufactured by binding the strands, particles, fibers

Wood fibre

Wood fibres are usually cellulosic elements that are extracted from trees, straw, bamboo, cotton seed, hemp, sugarcane and other sources.The end paper product dictates the species, or species blend, that is best suited to provide the desirable sheet characteristics, and also dictates the required...

, or veneers

Wood veneer

In woodworking, veneer refers to thin slices of wood, usually thinner than 3 mm , that are typically glued onto core panels to produce flat panels such as doors, tops and panels for cabinets, parquet floors and parts of furniture. They are also used in marquetry...

 of wood, together with adhesive

Adhesive

An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

s, to form composite material

Composite material

Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...

s. These products are engineered

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

 to precise design specifications which are tested to meet national or international standards. Engineered wood products are used in a variety of applications, from home construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in many building projects.

Typically, engineered wood products are made from the same hardwood

Hardwood

Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...

s and softwood

Softwood

The term softwood is used to describe wood from trees that are known as gymnosperms.Conifers are an example. It may also be used to describe trees, which tend to be evergreen, notable exceptions being bald cypress and the larches....

s used to manufacture lumber

Lumber

Lumber or timber is wood in any of its stages from felling through readiness for use as structural material for construction, or wood pulp for paper production....

. Sawmill

Sawmill

A sawmill is a facility where logs are cut into boards.-Sawmill process:A sawmill's basic operation is much like those of hundreds of years ago; a log enters on one end and dimensional lumber exits on the other end....

 scraps and other wood waste can be used for engineered wood composed of wood particles or fibers, but whole logs are usually used for veneers, such as plywood

Plywood

Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...

, MDF

Medium-density fibreboard

Medium-density fiberboard is an engineered wood product formed by breaking down hardwood or softwood residuals into wood fibres, often in a defibrator, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure...

 or Particle board

Particle board

Particle board, or particleboard , is an engineered wood product manufactured from wood particles, such as wood chips, sawmill shavings, or even saw dust, and a synthetic resin or other suitable binder, which is pressed and extruded...

. Some engineered wood products, like oriented strand board (OSB), can use trees from the poplar family, a common but non-structural species. Alternatively, it is also possible to manufacture similar engineered cellulosic

Cellulose

Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

 products from other lignin

Lignin

Lignin or lignen is a complex chemical compound most commonly derived from wood, and an integral part of the secondary cell walls of plants and some algae. The term was introduced in 1819 by de Candolle and is derived from the Latin word lignum, meaning wood...

-containing materials such as rye

Rye

Rye is a grass grown extensively as a grain and as a forage crop. It is a member of the wheat tribe and is closely related to barley and wheat. Rye grain is used for flour, rye bread, rye beer, some whiskeys, some vodkas, and animal fodder...

 straw, wheat

Wheat

Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...

 straw, rice

Rice

Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...

 straw, hemp

Hemp

Hemp is mostly used as a name for low tetrahydrocannabinol strains of the plant Cannabis sativa, of fiber and/or oilseed varieties. In modern times, hemp has been used for industrial purposes including paper, textiles, biodegradable plastics, construction, health food and fuel with modest...

 stalks, kenaf

Kenaf

Kenaf [Etymology: Persian], Hibiscus cannabinus, is a plant in the Malvaceae family. Hibiscus cannabinus is in the genus Hibiscus and is probably native to southern Asia, though its exact natural origin is unknown. The name also applies to the fibre obtained from this plant...

 stalks, or sugar cane residue, in which case they contain no actual wood but rather vegetable fibers.
Flat pack furniture is typically made out of man-made wood due to its low manufacturing costs and its low weight, making it easy to transport

Types of products

• Plywood
  Plywood
  Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...
  
  ,a wood structural panel, is sometimes called the original engineered wood product. Plywood is manufactured from sheets of cross-laminated veneer and bonded under heat and pressure with durable, moisture-resistant adhesives. By alternating the grain direction of the veneers from layer to layer, or “cross-orienting”, panel strength and stiffness in both directions are maximized. Other structural wood panels include oriented strand board and structural composite panels.
• Oriented strand board
  Oriented strand board
  Oriented strand board, also known as OSB and SmartPly , is an engineered wood product formed by layering strands of wood in specific orientations. In appearance, it may have a rough and variegated surface with the individual strips Oriented strand board, also known as OSB (UK) and SmartPly (UK &...
  
   (OSB) is a wood structural panel manufactured from rectangular-shaped strands of wood that are oriented lengthwise and then arranged in layers, laid up into mats, and bonded together with moisture-resistant, heat-cured adhesives. The individual layers are cross-oriented to provide strength and stiffness to the panel. Produced in huge, continuous mats, OSB is a solid panel product of consistent quality with no laps, gaps or voids.
• Glued laminated timber
  Glued laminated timber
  Glued laminated timber, also called Glulam, is a type of structural timber product composed of several layers of dimensioned timber bonded together with durable, moisture-resistant adhesives. This material is called 'laminating stock' or lamstock for short.By laminating several smaller pieces of...
  
   (glulam) is composed of several layers of dimensional timber glued together with moisture-resistant adhesives, creating a large, strong, structural member that can be used as vertical columns or horizontal beams. Glulam can also be produced in curved shapes, offering extensive design flexibility.
• Laminated veneer lumber (LVL) is produced by bonding thin wood veneers together in a large billet. The grain of all veneers in the LVL billet is parallel to the long direction. The resulting product features enhanced mechanical properties and dimensional stability that offer a broader range in product width, depth and length than conventional lumber. LVL is a member of the structural composite lumber (SCL) family of engineered wood products that are commonly used in the same structural applications as conventional sawn lumber and timber, including rafters, headers, beams, joists, rim boards, studs and columns.
• Cross-Laminated Timber (CLT) is a versatile multi-layered panel made of lumber. Each layer of boards is placed cross-wise to adjacent layers for increased rigidity and strength. CLT can be used for long spans and all assemblies, e.g. floors, walls or roofs.
• Parallel strand lumber (PSL) consists of long veneer strands laid in parallel formation and bonded together with an adhesive to form the finished structural section. A strong, consistent material, it has a high load carrying ability and is resistant to seasoning stresses so it is well suited for use as beams and columns for post and beam construction, and for beams, headers, and lintels for light framing construction. PSL is a member of the structural composite lumber (SCL) family of engineered wood products.
• Laminated strand lumber (LSL) and oriented strand lumber (OSL) are manufactured from flaked wood strands that have a high length-to-thickness ratio. Combined with an adhesive, the strands are oriented and formed into a large mat or billet and pressed. LSL and OSL offer good fastener-holding strength and mechanical connector performance and are commonly used in a variety of applications, such as beams, headers, studs, rim boards, and millwork components. These products are members of the structural composite lumber (SCL) family of engineered wood products. .
• Finger-jointed lumber is made up of short pieces of wood combined to form longer lengths and is used in door jams, mouldings and studs. It is also produced in long lengths and wide dimensions for floors.
• I-joists are "I"-shaped structural members designed for use in floor and roof construction. An I-joist consists of top and bottom flanges of various widths united with webs of various depths. The flanges resist common bending stresses, and the web provides shear performance. I-joists are designed to carry heavy loads over long distances while using less lumber than a dimensional solid wood joist of a size necessary to do the same task [1]. As of 2005, approximately half of all wood light framed floors were framed using I-joists [2].
• Roof trusses are structural frames relying on a triangular arrangement of webs and chords to transfer loads to reaction points.

Engineered wood products are used in a variety of ways, often in applications similar to solid wood

Solid wood

Solid wood is a term most commonly used to distinguish between ordinary lumber and engineered wood, but it also refers to structures that do not have hollow spaces. Engineered wood products are manufactured by binding together wood strands, fibers, or veneers with adhesives to form a composite...

 products. Engineered wood products may be preferred over solid wood in some applications due to certain comparative advantages:

• Because engineered wood is man-made, it can be designed to meet application-specific performance requirements.
• Engineered wood products are versatile and available in a wide variety of thicknesses, sizes, grades, and exposure durability classifications, making the products ideal for use in unlimited construction, industrial and home project application.
• Engineered wood products are designed and manufactured to maximize the natural strength and stiffness characteristics of wood. The products are very stable and some offer greater structural strength than typical wood building materials. Eight-storey Stadthaus
  Stadthaus
  Stadthaus is a nine-storey residential building in Hackney, London. It is thought to be the tallest timber residential structure in the world...
  
  , an apartment complex in London, England, was made with cross-laminated timber panels and is the tallest habitable timber building in the world.
• Glued laminated timber (glulam) has greater strength and stiffness than comparable dimensional lumber and, pound for pound, is stronger than steel. Glulam products are also a better environmental choice than steel because they have less embodied energy.
• Some engineered wood products offer more design options without sacrificing structural requirements.
• Engineered wood panels are easy to work with using ordinary tools and basic skills. They can be cut, drilled, routed, jointed, glued, and fastened. Plywood can be bent to form curved surfaces without loss of strength. And large panel size speeds construction by reducing the number of pieces to be handled and installed.
• Engineered wood products provide the natural warmth and beauty of wood. Many products are available in a variety of surface textures and treatments for nearly every aesthetic taste, from rustic to elegant. The products can be easily and beautifully finished with paints, stains, and varnishes.
• Engineered wood products make more efficient use of wood. They can be made from small pieces of wood, wood that has defects or underutilized species.
• Roof trusses are competitive in many roof and floor applications, and their high strength-to-weight ratios permit long spans offering flexibility in floor layouts.

Engineered wood products also have some disadvantages:

• Some products may burn more quickly than solid lumber.
• They require more primary energy for their manufacture than solid lumber.
• The adhesive
  Adhesive
  An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...
  
  s used in some products may be toxic. A concern with some resins is the release of formaldehyde in the finished product, often seen with urea-formaldehyde bonded products.
• Cutting and otherwise working with some products can expose workers to toxic compounds.
• Some engineered wood products, such as those specified for interior use, may be weaker and more prone to humidity
  Humidity
  Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...
  
  -induced warping than equivalent solid woods. Most particle and fiber-based boards are not appropriate for outdoor use because they readily soak up water.

Adhesives

The types of adhesives used in engineered wood include:
Urea-formaldehyde

Urea-formaldehyde

Urea-formaldehyde, also known as urea-methanal, named so for its common synthesis pathway and overall structure, is a non-transparent thermosetting resin or plastic, made from urea and formaldehyde heated in the presence of a mild base such as ammonia or pyridine...

 resins (UF): most common, most cheap, and not waterproof.
Phenol

Phenol

Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...

-formaldehyde resins (PF): yellow/brown, and commonly used for exterior exposure products.
Melamine

Melamine

Melamine is an organic base and a trimer of cyanamide, with a 1,3,5-triazine skeleton. Like cyanamide, it contains 66% nitrogen by mass and, if mixed with resins, has fire retardant properties due to its release of nitrogen gas when burned or charred, and has several other industrial uses....

-formaldehyde resin (MF): white, heat and water resistant, and often used in exposed surfaces in more costly designs.
Methylene diphenyl diisocyanate

Methylene diphenyl diisocyanate

Methylene diphenyl diisocyanate, most often abbreviated as MDI, is an aromatic diisocyanate. It exists in three isomers, 2,2'-MDI, 2,4'-MDI, and 4,4'-MDI, but the 4,4' isomer is most widely used. This isomer is also known as Pure MDI. MDI reacts with polyols in the manufacture of polyurethane...

 (MDI) or polyurethane

Polyurethane

A polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...

 (PU) resins: expensive, generally waterproof, and do not contain formaldehyde.

A more inclusive term is structural composites. For example, fiber cement siding

Fiber cement siding

Fiber cement siding is a building material used to cover the exterior of a building in both commercial and domestic applications.-Usage:...

is made of cement and wood fiber, while cement board is a low density cement panel, often with added resin, faced with fiberglass mesh.