Engineered wood

Engineered wood, also called mass timber, composite wood, man-made wood, or manufactured board, includes a range of derivative wood products which are manufactured by binding or fixing the strands, particles, fibres, or veneers or boards of wood, together with adhesives, or other methods of fixation[1] to form composite material. The panels vary in size but can range upwards of 64 by 8 feet (19.5 by 2.4 m) and in the case of cross-laminated timber (CLT) can be of any thickness from a few inches to 16 inches (410 mm) or more.[2] These products are engineered to precise design specifications, which are tested to meet national or international standards and provide uniformity and predictability in their structural performance. Engineered wood products are used in a variety of applications, from home construction to commercial buildings to industrial products.[3] The products can be used for joists and beams that replace steel in many building projects.[4] The term mass timber describes a group of building materials that can replace concrete assemblies.[5] Broad-base adoption of mass timber and their substitution for steel and concrete in new mid-rise construction projects over the coming decades could help mitigate climate change.[6]

Very large self-supporting wooden roof. Built for Expo 2000, Hanover, Germany
75-unit apartment building, made largely of wood, in Mission, British Columbia

Typically, engineered wood products are made from the same hardwoods and softwoods used to manufacture lumber. Sawmill 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, medium-density fibreboard (MDF), or particle board. Some engineered wood products, like oriented strand board (OSB), can use trees from the poplar family, a common but non-structural species.

Wood-plastic composite, one kind of engineered wood

Alternatively, it is also possible to manufacture similar engineered bamboo from bamboo; and similar engineered cellulosic products from other lignin-containing materials such as rye straw, wheat straw, rice straw, hemp stalks, kenaf 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.

Types of productsEdit

 
Engineered wood products in a Home Depot store

There are a wide variety of engineered wood products for both structural and non-structural applications. This list is not comprehensive, and is intended to help categorize and distinguish between different types of engineered wood.

Wood-based panelsEdit

Wood structural panels are a collection of flat panel products, used extensively in building construction for sheathing, decking, cabinetry and millwork, and furniture. Examples include plywood and oriented strand board (OSB). Non-structural wood-based panels are flat-panel products, used in non-structural construction applications and furniture. Non-structural panels are usually covered with paint, wood veneer, or resin paper in their final form. Examples include fibreboard and particle board.[7]

PlywoodEdit

Plywood, a wood structural panel, is sometimes called the original engineered wood product.[8] 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 boards and structural composite panels.[9]

Oriented strand boardEdit

Oriented strand board (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 can be cross-oriented to provide strength and stiffness to the panel. Similar to plywood, most OSB panels are delivered with more strength in one direction. The wood strands in the outermost layer on each side of the board are normally aligned into the strongest direction of the board. Arrows on the product will often identify the strongest direction of the board (the height, or longest dimension, in most cases). Produced in huge, continuous mats, OSB is a solid panel product of consistent quality with no laps, gaps, or voids.[10] OSB is delivered in various dimensions, strengths, and levels of water resistance.

OSB and plywood are often used interchangeably in building construction.

FibreboardEdit

Medium-density fibreboard (MDF) and high-density fibreboard (hardboard or HDF) are made by breaking down hardwood or softwood residuals into wood fibers, combining them with wax and a resin binder, and forming panels by applying high temperature and pressure.[11] MDF is used in non-structural applications.

Particle boardEdit

Particle board is manufactured from wood chips, sawmill shavings, or even sawdust, and a synthetic resin or another suitable binder, which is pressed and extruded.[12] In recent time, research have shown that durable particle board can be produced from agricultural waste products, such as rice husk or guinea corn husk.[13] Particleboard is cheaper, denser, and more uniform than conventional wood and plywood and is substituted for them when the cost is more important than strength and appearance. A major disadvantage of particleboard is that it is very prone to expansion and discoloration due to moisture, particularly when it is not covered with paint or another sealer. Particle board is used in non-structural applications.

Structural composite lumberEdit

Structural composite lumber (SCL) is a class of materials made with layers of veneers, strands, or flakes bonded with adhesives. Unlike wood structural panels, structural composite lumber products generally have all grain fibers oriented in the same direction. The SCL family of engineered wood products are commonly used in the same structural applications as conventional sawn lumber and timber, including rafters, headers, beams, joists, rim boards, studs, and columns.[14] SCL products have higher dimensional stability and increased strength compared to conventional lumber products.

Laminated veneerEdit

Laminated veneer lumber (LVL) is produced by bonding thin wood veneers together in a large billet, similar to plywood. The grain of all veneers in the LVL billet is parallel to the long direction (unlike plywood). The resulting product features enhanced mechanical properties and dimensional stability that offer a broader range in product width, depth, and length than conventional lumber.

Parallel strandEdit

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. The length-to-thickness ratio of strands in PSL is about 300. 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.[14]

Laminated strandEdit

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. LSL is manufactured from relatively short strands—typically about 1 foot (0.30 m) long—compared to the 2-to-8-foot-long (0.61–2.44 m) strands used in PSL.[15] The length-to-thickness ratio of strands is about 150 for LSL and 75 for OSL.[14]

I-joistsEdit

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.[16] 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. As of 2005, approximately half of all wood light framed floors were framed using I-joists.[citation needed]

Mass timberEdit

Mass timber, also known as engineered timber, is a class of large structural wood components for building construction. Mass timber components are made of lumber or veneers bonded with adhesives or mechanical fasteners. Certain types of mass timber, such as nail-laminated timber and glue-laminated timber, have existed for over a hundred years.[17] Mass timber has enjoyed increasing popularity in the past decade, due to growing concern around the sustainability of building materials, and interest in prefabrication, off site construction, and modularization, for which mass timber is well suited. The various types of mass timber share the advantage of faster construction times as the components are manufactured off-site, and pre-finished to exact dimensions for simple on-site fastening.[18] Mass timber has been shown to have structural properties competitive with steel and concrete, opening the possibility to build large, tall buildings out of wood. Extensive testing has demonstrated the natural fire resistance properties of mass timber – primarily due the creation of a char layer around a column or beam which prevents fire from reaching the inner layers of wood.[2] In recognition of the proven structural and fire performance of mass timber, the International Building Code, a model code that forms the basis of many North American building codes, adopted new provisions in the 2021 code cycle that permit mass timber to be used in high-rise construction up to 18 stories.[19][20]

Cross-laminated timberEdit

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.[21]

Glue-laminated timberEdit

Glue-laminated timber (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.

Dowel-laminated timberEdit

Dowel-laminated timber (DLT) is a type of mass timber panel, similar to CLT, that is made by driving wooden dowels through a stack of parallel boards. Because all the wood fibers are oriented in the same direction, DLT can have slightly higher span strengths than CLT, but does not function as a shear diaphragm. Two advantages of DLT relative to CLT are the lack of any type of adhesives (the dowels are friction fit), and the ease of CNC-milling a variety of profiles into the edges of the boards.[22]

Nail-laminated timberEdit

Nail-laminated timber (NLT) is a type of mass timber panel, consisting of parallel boards fastened with nails.[23] It is one of the oldest types of mass timber, being used in warehouse construction during the Industrial Revolution. Like DLT, no chemical adhesives are used, and wood fibers are oriented in the same direction.

Engineered wood flooringEdit

Engineered wood flooring is a type of flooring product, similar to hardwood flooring, made of layers of wood or wood-based composite laminated together. The floor boards are usually milled with a tongue-and-groove profile on the edges for consistent joinery between boards.

LamellaEdit

The lamella is the face layer of the wood that is visible when installed. Typically, it is a sawn piece of timber. The timber can be cut in three different styles: flat-sawn, quarter-sawn, and rift-sawn.

Types of core/substrateEdit

  1. Wood ply construction ("sandwich core"): Uses multiple thin plies of wood adhered together. The wood grain of each ply runs perpendicular to the ply below it. Stability is attained from using thin layers of wood that have little to no reaction to climatic change. The wood is further stabilized due to equal pressure being exerted lengthwise and widthwise from the plies running perpendicular to each other.
  2. Finger core construction: Finger core engineered wood floors are made of small pieces of milled timber that run perpendicular to the top layer (lamella) of wood. They can be 2-ply or 3-ply, depending on their intended use. If it is three-ply, the third ply is often plywood that runs parallel to the lamella. Stability is gained through the grains running perpendicular to each other, and the expansion and contraction of wood are reduced and relegated to the middle ply, stopping the floor from gapping or cupping.
  3. Fibreboard: The core is made up of medium or high-density fibreboard. Floors with a fibreboard core are hygroscopic and must never be exposed to large amounts of water or very high humidity - the expansion caused by absorbing water combined with the density of the fibreboard, will cause it to lose its form. Fibreboard is less expensive than timber and can emit higher levels of harmful gases due to its relatively high adhesive content.
  4. An engineered flooring construction that is popular in parts of Europe is the hardwood lamella, softwood core laid perpendicular to the lamella, and a final backing layer of the same noble wood used for the lamella. Other noble hardwoods are sometimes used for the back layer but must be compatible. This is thought by many to be the most stable of engineered floors.

Other types of modified woodEdit

New techniques have been introduced in the field of engineered wood in recent years. Natural wood is being transformed in laboratories through various chemical and physical treatments to achieve tailored mechanical, optical, thermal, and conduction properties, by influencing the wood’s structure.

Densified woodEdit

Densified wood can be made by using a mechanical hot press to compress wood fibers, sometimes in combination with chemical modification of the wood. These processes have been shown to increase the density by a factor of three.[24] This increase in density is expected to enhance the strength and stiffness of the wood by a proportional amount.[25] More recent studies[26] have combined chemical processes with traditional mechanical hot press methods. These chemical processes break down lignin and hemicellulose that are found naturally in the wood. Following dissolution, the cellulose strands that remain are mechanically hot compressed. Compared to the three-fold increase in strength observed from hot pressing alone, chemically processed wood has been shown to yield an 11-fold improvement. This extra strength comes from hydrogen bonds formed between the aligned cellulose nanofibers.

The densified wood possessed mechanical strength properties on par with steel used in building construction, opening the door for applications of densified wood in situations where regular strength wood would fail. Environmentally, wood requires significantly less carbon dioxide to produce than steel.[27]

Thermally efficient woodEdit

Removing lignin from wood has several other applications, apart from providing structural advantages. Delignification alters the mechanical, thermal, optical, fluidic and ionic properties and functions of the natural wood and is an effective approach to regulating its thermal properties, as it removes the thermally conductive lignin component, while generating a large number of nanopores in the cell walls which help reduce temperature change. Delignified wood reflects most incident light and appears white in color.[28][29] White wood (also known as “nanowood”) has high reflection haze, as well as high emissivity in the infrared wavelengths. These two characteristics generate a passive radiative cooling effect, with an average cooling power of 53 W⋅m−2 over a 24-hour period,[29] meaning that this wood does not "absorb" heat and therefore only emits the heat embedded in it.[30] Moreover, white wood not only possesses a lower thermal conductivity than natural wood, and it has better thermal performance than most commercially available insulating materials.[28] The modification of the mesoporous structure of the wood is responsible for the changes in wood performance.[28][31]

White wood can also be put through a compression process, similar to the process mentioned for densified wood, which increases its mechanical performance compared to natural wood (8.7 times higher in tensile strength and 10 times higher in toughness).[29] The thermal and structural advantages of nanowood make it an attractive material for energy-efficient building construction.[31] However, the changes made in the wood’s structural properties, like the increase in structural porosity and the partially isolated cellulose nanofibrils, damage the material’s mechanical robustness. To deal with this issue, several strategies have been proposed, with one being to further densify the structure, and another to use cross-linking. Other suggestions include hybridizing natural wood with other organic particles and polymers to enhance its thermal insulation performance.[28]

Moldable woodEdit

Using similar chemical modification techniques to chemically densified wood, wood can be made extremely moldable using a combination of delignification and water shock treatment. This is an emerging technology and is not yet used in industrial processes. However, initial tests show promising advantages in improved mechanical properties, with the molded wood exhibiting strength comparable to some metal alloys.[32]

Transparent wood compositesEdit

Transparent wood composites are new materials, currently only made at the laboratory scale, that combines transparency and stiffness via a chemical process that replaces light-absorbing compounds, such as lignin, with a transparent polymer.[33]

Environmental benefitsEdit

Engineered wood has the potential to reduce carbon emissions by replacing cement and steel as a primary material in the construction of buildings.[34] Not only do buildings made from engineered wood act as a carbon sink, but they also produce less emissions in the manufacturing process than steel and cement, which both emit a lot of carbon dioxide (CO2) due to the chemical processes involved in their manufacturing.[35] For example, in 2014, steel and cement production accounted for about 1320 megatonnnes (Mt) CO2 and 1740 Mt CO2 respectively, which made up about 9% of global CO2 emissions that year.[36] In a study that did not take the carbon sequestration potential of engineered wood into account, it was found that roughly 50 Mt CO2e (carbon dioxide equivalent[a]) could be eliminated by 2050 with the full uptake of a hybrid construction system utilizing engineered wood and steel.[38] When considering the added effects that carbon sequestration can have over the lifetime of the material, the emissions reductions of engineered wood is even more substantial, as laminated wood that is not incinerated at the end of its lifecycle absorbs around 582 kg of CO2/m3, while reinforced concrete emits 458 kg CO2/m3 and steel 12.087 kg CO2/m3.[39]

There is not a strong consensus for measuring the carbon sequestration potential of wood. In life-cycle assessment, sequestered carbon is sometimes called biogenic carbon. ISO 21930, a standard that governs life cycle assessment, requires the biogenic carbon from a wood product can only be included as a negative input (i.e. carbon sequestration) when the wood product originated in a sustainably managed forest. This generally means that wood needs to be FSC or SFI-certified to qualify as carbon sequestering.[40]

Comparison to solid woodEdit

AdvantagesEdit

Engineered wood products are used in a variety of ways,[41] often in applications similar to solid wood 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. Required shapes and dimension do not drive source tree requirements (length or width of the tree)
  • 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.[42]
  • 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.[43]
  • Glued laminated timber (glulam) has greater strength and stiffness than comparable dimensional lumber and, pound for pound, is stronger than steel.[3]
  • Some engineered wood products offer more design options without sacrificing structural requirements.[citation needed]
  • 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.[42]
  • 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.[44]
  • Wooden trusses are competitive in many roof and floor applications, and their high strength-to-weight ratios permit long spans offering flexibility in floor layouts.[45]
  • Engineered wood is felt to offer structural advantages for home construction.[citation needed]
  • Sustainable design advocates recommend using engineered wood, which can be produced from relatively small trees, rather than large pieces of solid dimensional lumber, which requires cutting a large tree.[15]

DisadvantagesEdit

  • They require more primary energy for their manufacture than solid lumber.[46]
  • The adhesives 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.[46]
  • Cutting and otherwise working with some products can expose workers to toxic compounds.[citation needed]
  • Some engineered wood products, such as those specified for interior use, may be weaker and more prone to humidity-induced warping than equivalent solid woods. Most particle and fiber-based boards are not appropriate for outdoor use because they readily soak up water.[citation needed]

PropertiesEdit

Plywood and OSB typically have a density of 560–640 kg/m3 (35–40 lb/cu ft). For example, 9.5 mm (38 in) plywood sheathing or OSB sheathing typically has a surface density of 4.9–5.9 kg/m2 (1–1.2 lb/sq ft).[47] Many other engineered woods have densities much higher than OSB.

AdhesivesEdit

The types of adhesives used in engineered wood include:

A more inclusive term is structural composites. For example, fiber cement siding is made of cement and wood fiber, while cement board is a low-density cement panel, often with added resin, faced with fiberglass mesh.

Health concernsEdit

While formaldehyde is an essential ingredient of cellular metabolism in mammals, studies have linked prolonged inhalation of formaldehyde gases to cancer. Engineered wood composites have been found to emit potentially harmful amounts of formaldehyde gas in two ways: unreacted free formaldehyde and the chemical decomposition of resin adhesives. When exorbitant amounts of formaldehyde are added to a process, the excess will not have any additive to bond with and may seep from the wood product over time. Cheap urea-formaldehyde (UF) adhesives are largely responsible for degraded resin emissions. Moisture degrades the weak UF molecules, resulting in potentially harmful formaldehyde emissions. McLube offers release agents and platen sealers designed for those manufacturers who use reduced-formaldehyde UF and melamine-formaldehyde adhesives. Many oriented strand board (SB) and plywood manufacturers use phenol-formaldehyde (PF) because phenol is a much more effective additive. Phenol forms a water-resistant bond with formaldehyde that will not degrade in moist environments. PF resins have not been found to pose significant health risks due to formaldehyde emissions. While PF is an excellent adhesive, the engineered wood industry has started to shift toward polyurethane binders like pMDI to achieve even greater water resistance, strength, and process efficiency. pMDIs are also used extensively in the production of rigid polyurethane foams and insulators for refrigeration. pMDIs outperform other resin adhesives, but they are notoriously difficult to release and cause buildup on tooling surfaces.[48]

Mechanical fastenersEdit

Some engineered wood products, such as DLT, NLT, and some brands of CLT, can be assembled without the use of adhesives using mechanical fasteners or joinery. These can range from profiled interlocking jointed boards,[49][50] proprietary metal fixings,[51] nails or timber dowels.[22]

StandardsEdit

The following standards are related to engineered wood products:

  • EN 300 - Oriented Strand Boards (OSB) — Definitions, classification, and specifications
  • EN 309 - Particleboards — Definition and classification
  • EN 338 - Structural timber - Strength classes
  • EN 386 - Glued laminated timber — performance requirements and minimum production requirements
  • EN 313-1 - Plywood — Classification and terminology Part 1: Classification
  • EN 313-2 - Plywood — Classification and terminology Part 2: Terminology
  • EN 314-1 - Plywood — Bonding quality — Part 1: Test methods
  • EN 314-2 - Plywood — Bonding quality — Part 2: Requirements
  • EN 315 - Plywood — Tolerances for dimensions
  • EN 387 - Glued laminated timber — large finger joints - performance requirements and minimum production requirements
  • EN 390 - Glued laminated timber — sizes - permissible deviations
  • EN 391 - Glued laminated timber — shear test of glue lines
  • EN 392 - Glued laminated timber — Shear test of glue lines
  • EN 408 - Timber structures — Structural timber and glued laminated timber — Determination of some physical and mechanical properties
  • EN 622-1 - Fibreboards — Specifications — Part 1: General requirements
  • EN 622-2 - Fibreboards — Specifications — Part 2: Requirements for hardboards
  • EN 622-3 - Fibreboards — Specifications — Part 3: Requirements for medium boards
  • EN 622-4 - Fibreboards — Specifications — Part 4: Requirements for soft boards
  • EN 622-5 - Fibreboards — Specifications — Part 5: Requirements for dry process boards (MDF)
  • EN 1193 - Timber structures — Structural timber and glued laminated timber - Determination of shear strength and mechanical properties perpendicular to the grain
  • EN 1194 - Timber structures — Glued laminated timber - Strength classes and determination of characteristic values
  • EN 1995-1-1 - Eurocode 5: Design of timber structures — Part 1-1: General — Common rules and rules for buildings
  • EN 12369-1 - Wood-based panels — Characteristic values for structural design — Part 1: OSB, particleboards, and fibreboards
  • EN 12369-2 - Wood-based panels — Characteristic values for structural design — Part 2: Plywood
  • EN 12369-3 - Wood-based panels — Characteristic values for structural design — Part 3: Solid wood panels
  • EN 14080 - Timber structures — Glued laminated timber — Requirements
  • EN 14081-1 - Timber structures - Strength graded structural timber with rectangular cross-section - Part 1: General requirements
  • ISO 21930:2017 - Sustainability in buildings and civil engineering works - Core rules for environmental product declarations of construction products and services

See alsoEdit

  • Ascent MKE - Tallest mass timber building in the world
  • Stadthaus - Application sample for timber panels

NotesEdit

  1. ^ Carbon dioxide equivalent (CO2e) is a way of measuring the global warming potential of multiple greenhouse gases using a common unit. 1 kg of methane emissions, for instance, has the same global warming potential as 25 kg of CO2 emissions, so 1 kg of methane emissions can be reported as 25 kg CO2e.[37]

ReferencesEdit

  1. ^ "Brettsperrholz". dataholz.com.
  2. ^ a b Green, Michael (2011). The Case for Tall Wood Buildings.
  3. ^ a b A Guide To Engineered Wood Products, Form C800. Apawood.org. Retrieved on February 10, 2012.
  4. ^ Naturally:wood Engineered wood Archived May 22, 2016, at the Portuguese Web Archive. Naturallywood.com. Retrieved on February 15, 2012.
  5. ^ "Mass Timber in North America" (PDF). American Wood Council. November 8, 2018. Retrieved February 7, 2020.
  6. ^ "Why Not Wood? (Mass-Timber Construction) – Debating Science". Retrieved November 1, 2022.
  7. ^ Allen, Edward (2019). Fundamentals of building construction : materials and methods. Joseph Iano (Seventh ed.). Hoboken, New Jersey. ISBN 1-119-45024-1. OCLC 1081381140.
  8. ^ "Milestones in the History of Plywood" Archived July 17, 2011, at the Wayback Machine, APA – The Engineered Wood Association. Accessed October 22, 2007.
  9. ^ APA A glossary of Engineered Wood Terms Archived November 26, 2010, at the Wayback Machine. Apawood.org. Retrieved on February 10, 2012.
  10. ^ Oriented Strand Board Product Guide, Form W410. Apawood.org. Retrieved on February 10, 2012.
  11. ^ Corky Binggeli. (2013), "Materials for Interior Environments".
  12. ^ Cheever, Ellen; Association), NKBA (National Kitchen and Bath (November 10, 2014). Kitchen & Bath Products and Materials: Cabinetry, Equipment, Surfaces. John Wiley & Sons. ISBN 978-1-118-77528-8.
  13. ^ Ciannamea, E. M.; Marin, D. C.; Ruseckaite, R. A.; Stefani, P. M. (October 14, 2017). "Particleboard Based on Rice Husk: Effect of Binder Content and Processing Conditions". Journal of Renewable Materials. 5 (5): 357–362. doi:10.7569/JRM.2017.634125. ISSN 2164-6325.
  14. ^ a b c "Structural Composite Lumber (SCL) - APA – The Engineered Wood Association". www.apawood.org. Retrieved November 13, 2022.
  15. ^ a b Mary McLeod et al. "Guide to the single-family home rating" Archived October 11, 2007, at the Wayback Machine. Austin Energy Green Building. HARSHITA p. 31-32.
  16. ^ APA – The Engineered Wood Association Archived February 21, 2011, at the Wayback Machine. Apawood.org. Retrieved on February 10, 2012.
  17. ^ Lehman, Eben (October 15, 2018). "October 15, 1934: Glued Laminated Timber Comes to America". Forest History Society. Retrieved November 12, 2022.{{cite web}}: CS1 maint: url-status (link)
  18. ^ Kaufmann, Hermann; Krötsch, Stefan; Winter, Stefan (October 24, 2022). Manual of Multistorey Timber Construction. DETAIL. doi:10.11129/9783955535827. ISBN 978-3-95553-582-7.
  19. ^ Breneman, Scott; Timmers, Matt; Richardson, Dennis (August 22, 2019). "Tall Wood Buildings and the 2021 IBC: Up to 18 Stories of Mass Timber" (PDF). Woodworks. Retrieved November 19, 2022.{{cite web}}: CS1 maint: url-status (link)
  20. ^ IBC 2021 : International Building Code. International Code Council. Country Club Hills. 2020. ISBN 978-1-60983-955-0. OCLC 1226111757.{{cite book}}: CS1 maint: others (link)
  21. ^ FPInnovations Cross-Laminated Timber: A Primer. (PDF) . Retrieved on February 10, 2012.
  22. ^ a b Sotayo, Adeayo; Bradley, Daniel; Bather, Michael; Sareh, Pooya; Oudjene, Marc; El-Houjeyri, Imane; Harte, Annette M.; Mehra, Sameer; O'Ceallaigh, Conan; Haller, Peer; Namari, Siavash; Makradi, Ahmed; Belouettar, Salim; Bouhala, Lyazid; Deneufbourg, François (February 1, 2020). "Review of state of the art of dowel laminated timber members and densified wood materials as sustainable engineered wood products for construction and building applications". Developments in the Built Environment. 1: 100004. doi:10.1016/j.dibe.2019.100004. ISSN 2666-1659.
  23. ^ "Nail Laminated Timber Construction | NLT Lumber". Think Wood. Retrieved November 13, 2022.
  24. ^ Erickson, E.C.O. (1965). "Mechanical properties of laminated modified wood". ScholarsArchive@OSU. Forest Products Laboratory.
  25. ^ Ashby, M. F.; Medalist, R. F. Mehl (September 1, 1983). "The mechanical properties of cellular solids". Metallurgical Transactions A. 14 (9): 1755–1769. Bibcode:1983MTA....14.1755A. doi:10.1007/BF02645546. ISSN 0360-2133. S2CID 135765088.
  26. ^ Song, Jianwei; Chen, Chaoji; Zhu, Shuze; Zhu, Mingwei; Dai, Jiaqi; Ray, Upamanyu; Li, Yiju; Kuang, Yudi; Li, Yongfeng (February 2018). "Processing bulk natural wood into a high-performance structural material". Nature. 554 (7691): 224–228. Bibcode:2018Natur.554..224S. doi:10.1038/nature25476. ISSN 1476-4687. PMID 29420466. S2CID 4469909.
  27. ^ Ramage, Michael H.; Burridge, Henry; Busse-Wicher, Marta; Fereday, George; Reynolds, Thomas; Shah, Darshil U.; Wu, Guanglu; Yu, Li; Fleming, Patrick; Densley-Tingley, Danielle; Allwood, Julian; Dupree, Paul; Linden, P.F.; Scherman, Oren (February 1, 2017). "The wood from the trees: The use of timber in construction". Renewable and Sustainable Energy Reviews. 68: 333–359. doi:10.1016/j.rser.2016.09.107. ISSN 1364-0321.
  28. ^ a b c d Chen, Chaoji; Kuang, Yudi; Zhu, Shuze; Burgert, Ingo; Keplinger, Tobias; Gong, Amy; Li, Teng; Berglund, Lars; Eichhorn, Stephen J.; Hu, Liangbing (September 2020). "Structure–property–function relationships of natural and engineered wood". Nature Reviews Materials. 5 (9): 642–666. doi:10.1038/s41578-020-0195-z. ISSN 2058-8437.
  29. ^ a b c Mao, Yimin; Hu, Liangbing; Ren, Zhiyong Jason (May 4, 2022). "Engineered wood for a sustainable future". Matter. 5 (5): 1326–1329. doi:10.1016/j.matt.2022.04.013. ISSN 2590-2385.
  30. ^ "What is Radiation Cooling?". www.hko.gov.hk. Retrieved December 1, 2022.
  31. ^ a b Kumar, Anuj; Jyske, Tuula; Petrič, Marko (May 2021). "Delignified Wood from Understanding the Hierarchically Aligned Cellulosic Structures to Creating Novel Functional Materials: A Review". Advanced Sustainable Systems. 5 (5): 2000251. doi:10.1002/adsu.202000251. ISSN 2366-7486.
  32. ^ Xiao, Shaoliang; Chen, Chaoji; Xia, Qinqin; Liu, Yu; Yao, Yuan; Chen, Qiongyu; Hartsfield, Matt; Brozena, Alexandra; Tu, Kunkun; Eichhorn, Stephen J.; Yao, Yonggang (October 22, 2021). "Lightweight, strong, moldable wood via cell wall engineering as a sustainable structural material". Science. 374 (6566): 465–471. Bibcode:2021Sci...374..465X. doi:10.1126/science.abg9556. ISSN 0036-8075. PMID 34672741. S2CID 239455815.
  33. ^ Mi, Ruiyu; Li, Tian; Dalgo, Daniel; Chen, Chaoji; Kuang, Yudi; He, Shuaiming; Zhao, Xinpeng; Xie, Weiqi; Gan, Wentao; Zhu, Junyong; Srebric, Jelena; Yang, Ronggui; Hu, Liangbing (January 2020). "A Clear, Strong, and Thermally Insulated Transparent Wood for Energy Efficient Windows". Advanced Functional Materials. 30 (1): 1907511. doi:10.1002/adfm.201907511. ISSN 1616-301X.
  34. ^ Roberts, David (January 15, 2020). "The hottest new thing in sustainable building is, uh, wood". Vox. Archived from the original on August 14, 2022.
  35. ^ Churkina, Galina; Organschi, Alan; Reyer, Christopher P. O.; Ruff, Andrew; Vinke, Kira; Liu, Zhu; Reck, Barbara K.; Graedel, T. E.; Schellnhuber, Hans Joachim (April 2020). "Buildings as a global carbon sink". Nature Sustainability. 3 (4): 269–276. doi:10.1038/s41893-019-0462-4. ISSN 2398-9629.
  36. ^ Davis, Steven J. (2018). "Net-zero emissions energy systems". Science. 360 (6396). doi:10.1126/science.aas9793. PMID 29954954. S2CID 206666797. Retrieved November 18, 2021.
  37. ^ Brander, Matthew (August 2012). "Greenhouse Gases, CO 2, CO 2 e, and Carbon: What Do All These Terms Mean?" (PDF). Econometrica. Archived (PDF) from the original on June 28, 2022.
  38. ^ D'Amico, Bernardino; Pomponi, Francesco; Hart, Jim (2021). "Global potential for material substitution in building construction: The case of cross laminated timber". Journal of Cleaner Production. 279: 123487. doi:10.1016/j.jclepro.2020.123487. S2CID 224927490. Retrieved November 18, 2021.
  39. ^ Zabalza Bribián, Ignacio; Valero Capilla, Antonio; Aranda Usón, Alfonso (2011). "Life cycle assessment of building materials: Comparative analysis of energy and environmental impacts and evaluation of the eco-efficiency improvement potential". Building and Environment. 46 (5): 1133–1140. doi:10.1016/j.buildenv.2010.12.002. Retrieved November 18, 2021.
  40. ^ Breton, Charles; Blanchet, Pierre; Amor, Ben; Beauregard, Robert; Chang, Wen-Shao (June 14, 2018). "Assessing the Climate Change Impacts of Biogenic Carbon in Buildings: A Critical Review of Two Main Dynamic Approaches". Sustainability. 10 (6). doi:10.3390/su10062020. ISSN 2071-1050.
  41. ^ "The Advantages of Engineered Hardwood Flooring". Really Cheap Floors. June 9, 2018. Retrieved May 10, 2019.
  42. ^ a b Wood University. Wood University. Retrieved on February 10, 2012.
  43. ^ Naturally:wood engineered wood Archived May 22, 2016, at the Portuguese Web Archive. Naturallywood.com. Retrieved on February 10, 2012.
  44. ^ APA Engineered Wood and the Environment: Facts and Figures Archived January 27, 2011, at the Wayback Machine. Apawood.org. Retrieved on February 10, 2012.
  45. ^ Naturally: wood Engineered wood. Naturallywood.com. Retrieved on February 10, 2012.
  46. ^ a b Johnson, Chad (February 22, 2017). "Wood Composite - The Alternative, Sustainable Solution to Timber". Build Abroad. Retrieved September 30, 2020.
  47. ^ "Weights of building materials -- pounds per square foot (PSF)"[permanent dead link]. Boise Cascade: Engineered wood products. 2009.
  48. ^ "Formaldehyde in pressed wood products". www.nicnas.gov.au. Retrieved March 12, 2018.
  49. ^ "Interlocking Cross Laminated Timber Could Use Up Square Miles Of Beetle-Killed Lumber, and Look Gorgeous, Too". treehugger.com.
  50. ^ "Wohnen und Leben mit der Natur". soligno.com. Archived from the original on December 17, 2013. Retrieved December 17, 2013.
  51. ^ "Unsere Leistungen im Überblick". April 25, 2011.

External linksEdit