Civil Engineering

Understanding wood structural panels

  • Wood structural panels which is also known as engineered wood panels are widely used in homes and offices today as they give modernize look to the space. Engineering wood refers to a variety of derivative wood products that are created by binding or fixing wood fibers, veneers, or boards with adhesives or other fixation techniques to create composite material. Well, in this article, the following question about wood structural panels will be discussed:
    What is wood structural panels?
  • What are the applications of wood structural panels?
  • What are the properties of engineered wood?
  • what are the types of wood structural panels?
  • What are the benefits and limitations of engineered wood?

Now, let’s dive in!

wood structural panels

Read more: Types of wood and their uses

What is wood structural panels?

Engineered wood, also known as mass timber, composite wood, man-made wood, or produced board, refers to a variety of wood-derived goods that are created by binding or fastening wood fibers, veneers, or boards together with adhesives or other fixatives to create composite material.

A wood structural panel is described as “a panel produced from veneers; or wood strands or wafers; bound together with waterproof synthetic resins or other acceptable bonding techniques” in the 2018 International Residential Code (IRC), which was released by the International Code Council (ICC). Plywood, oriented strand board (OSB), and composite panels are a few types of wood structural panels.

The panels can be any thickness between a few millimeters and 16 inches (410 mm) or more when made of cross-laminated timber (CLT), and their sizes can range from a few inches to 64 by 8 feet (19.5 by 2.4 m) or more. To ensure uniformity and predictability in their structural performance, these items are engineered to precise design requirements, tested to satisfy national or international standards, and then produced.

What are the applications of wood structural panels?

Typically, the same hardwoods and softwoods used to produce lumber are employed to create engineered wood products. Engineered wood made of wood fibers or particles can be made from sawmill scraps and other wood waste, but veneers like plywood, medium-density fiberboard (MDF), and particle board are typically made from complete logs. Oriented strand board (OSB), an engineered wood product, is one that uses trees from the poplar family, a common but non-structural species.

Wood structural panels are used in many different applications, including industrial goods, commercial buildings, and house construction. In many construction projects, the goods can be utilized in place of steel for joists and beams. A class of building materials that can take the place of concrete assemblies are referred to as mass wood. In the upcoming decades, widespread adoption of mass timber and its replacement with steel and concrete in new mid-rise construction projects could aid in reducing climate change.

Read more: Understanding wood

The followings are the applications of structural panels in construction: 

  • Floors
  • Walls
  • Roofs

 

Floors

The most typical wood structural panel used as a subfloor and underlayment in ordinary floor applications is 23/32-inch thick, installed at 24 inches on center (Figures 10a and 10b). These panels offer a sturdy, stiff, and solid surface on which various types of finish flooring (such carpet and pad) can be put directly, with supports at 24 inches on-center or less.
Many applications also make use of a two-layer floor system, which consists of an underlayment layer and a structural subflooring layer.

Walls

Wood structural panels prevent racking along the walls (caused by earthquakes and wind) and keep walls erect (Figures 11 and 12). In other instances, the wood structural panel bracing system is replaced by wall sheathing made of cardboard, foam plastic, or other materials.

Roofs

Under various waterproofing systems, wood structural panels are frequently utilized as roof sheathing on pitched and flat roofs. They support the weight of humans, mechanical equipment, and gravity loads from snow, rain, and finished roofs while also protecting buildings from lateral stresses caused by strong winds or earthquakes. 7/16″ and 15/32″ are the most popular panel thicknesses used in roofs. Trusses typically spaced 24″ on center support them. Building standards often allow wood structural panels as thin as 3/8″ thick in roofs with supports up to 24″ oc in regions with little to no snow loads.

STRUCTURAL-WOOD-PANELS

Read more: Different types of wood finishes and finishing products

What are the properties of engineered wood?

There are numerous ways to use wood to meet the physical requirements in industry, however most of these methods operate on a macro scale and do not alter the microstructure or material qualities. In order to simultaneously attain high mechanical strength and acceptable moldability, failure occurs. There are methods to create wood that is both highly mechanically durable and moldable.

Natural wood is partially delignified and softened in the process, and then its fibers and vessels are shrunk by drying. Finally, the material is “shocked” with water to selectively open the vessels. Water shock creates crumpled fiber cell walls and partially open capillaries. Because of its microstructure, wood can flex and mold. By using scanning electron microscopy (SEM), it is possible to see that the fibers of the moldable wood are tightly packed together and that some of the vessels have partially opened as a result of the water shock process.

The mechanical properties of engineered panels or wood include bending test, tensile strength, and compressive strength.

Read more: Understanding wood finishing

What are the types of wood structural panels?

The followings are the common types of wood structural panels:

  • Plywood
  • Densified wood
  • Fibreboard
  • Particle board
  • Oriented strand board
  • Laminated timber
  • Laminated veneer
  • Cross laminated timber

 

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Plywood

The first engineered wood product is sometimes known to as plywood, a structural wood panel. Sheets of cross-laminated veneer are used to create plywood, which is then bonded with strong, moisture-resistant adhesives using heat and pressure. Panel strength and stiffness in both directions are increased by “cross-orienting,” or switching the veneers’ grain orientation from layer to layer. Oriented strand boards and structural composite panels are examples of further structural wood panels.

Densified wood

Wood fibers are mechanically compressed in a hot press to enhance density by a factor of three, creating densified wood. It is anticipated that this increase in density will proportionally improve the wood’s strength and stiffness. Early research supported these findings, which included a three-fold increase in mechanical strength.

Fibreboard

In order to create medium-density fiberboard and high-density fiberboard (hardboard), residual hardwood or softwood wood is converted into wood fibers, which are then mixed with wax and a resin binder before being formed into panels under high heat and pressure.

Particle board

Wood chips, shavings from sawmills, or even sawdust, along with a synthetic resin or other suitable binder, are pressed and extruded to create particle board. Similar materials are used in oriented strand board, sometimes referred to as flakeboard, wafer board, or chipboard, but it uses machined wood flakes for greater strength. When economy is more essential than strength and appearance, particleboard is replaced for standard wood and plywood since it is less expensive, denser, and more uniform. Particleboard has a significant drawback in that it is quite susceptible to moisture-related expansion and discoloration, especially if it is not painted or otherwise sealed.

Read more: Different types of wood joints and their working

Oriented strand board

A wood structural panel known as Oriented Strand Board (OSB) is made from rectangular wood strands that are oriented longitudinally, layered, laid up into mats, and joined together with moisture-resistant, heat-cured adhesives. To give the panel strength and rigidity, the individual layers might be cross-oriented. However, the majority of OSB panels are more strongly delivered in one direction. Normally, the board’s strongest direction is aligned with the wood strands in the outermost layer on both sides. The strongest direction of the board will frequently be indicated by arrows on the product (the height, or longest dimension, in most cases). OSB is a solid panel product of consistent quality that is made in enormous, continuous mats with no laps, gaps, or cavities.

Laminated timber

Glued laminated timber (glulam) is a structural material that can be used as horizontal or vertical beams or columns. It is made up of numerous layers of dimensional wood that are glued together with moisture-resistant adhesives. Additionally, glulam can be made in curved forms, providing a wide range of design flexibility.

Laminated veneer

Thin wood veneers are bonded together in a big billet to create laminated veneer lumber (LVL). Every veneer in the LVL billet has a grain that runs parallel to the long direction. The end result offers a wider range in product breadth, depth, and length than standard timber because to improved mechanical qualities and dimensional stability. In the same structural uses as traditional sawn lumber and timber, such as rafters, headers, beams, joists, rim boards, studs, and columns, LVL is a member of the structural composite lumber (SCL) family of engineered wood products.

Cross laminated timber

A multi-layered panel composed of lumber called cross-laminated timber (CLT) is adaptable and durable. For greater rigidity and strength, boards are arranged crosswise to one another. Long spans and all assemblies, such as floors, walls, or roofs, can be built with CLT. [15] Because the panels are produced and completed off-site and delivered ready to fit and screw together as a flat pack assembly project, CLT has the advantage of quicker building timelines.

Insulated Structural Panels

Structural insulated panels (SIPs) are composites made of expanded polystyrene (EPS) foam material placed between structural panels made of wood. SIPs are used to construct roofs, walls, and floors. SIPs are utilized due to their energy effectiveness. Typically, EPS is covered with 7/16″ OSB skins. The EPS in SIPs can be as thick as a foot, making them perfect for cold areas.
The electrical and plumbing chases are already in place, all the apertures and shapes are precut, and SIPs are manufactured in a factory. The building may be enclosed in two or three days once the foundations are set. Then, exactly like with a field-built building, gypsum wallboard is applied to the inside surface of the SIPs.

woof structural panels

Read more: Understanding woodworking joints

What are the benefits and limitations of engineered wood?

The followings are the advantages and disadvantages of wood structural panels or engineered panels in their various applications:

Advantages:

  • Engineered wood can be manufactured to meet the performance requirements of specific application because it is man-made. Source tree requirements are not determined by required forms and dimensions (length or width of the tree)
  • Because they are flexible and come in a wide range of thicknesses, widths, grades, and exposed durability classifications, wood structural panels are perfect for usage in a wide range of construction, industrial, and domestic projects.
  • Engineered wood products are created in a way that maximizes the strength and stiffness that wood naturally possesses. Some of the items have more structural strength than normal wood building materials and are very stable.
  • Glued laminated wood (glulam) is more rigid and sturdy than comparable dimensional lumber, and it is more powerful than steel pound for pound.
  • More design options without losing structural requirements are provided by some engineered wood products.
  • Engineered wood panels are simple to deal with when using common tools and fundamental knowledge. They are able to be joined, routed, cut, drilled, glued, and fixed. Without losing strength, plywood may be bent to make curved surfaces. Large panel size also expedites construction by minimizing the amount of handling and installation required for each piece.
  • Wood structural panels use wood more effectively. They can be produced from sparsely used species, flawed timber, or little bits of wood.
  • The flexibility of wooden trusses’ broad spans and strong strength-to-weight ratios allow them to be used in a variety of roof and floor applications.
  • Engineered wood is said to have structural benefits for the building of homes.
  • The use of engineered wood, which can be made from relatively tiny trees, is advised by proponents of sustainable design as opposed to massive pieces of solid dimensional timber, which require the chopping of a large tree.

 

Read more: Working of drilling machine on wood & metal

Disadvantages:

  • Compared to solid lumber, they take more primary energy to create.
  • Some objects’ adhesives could be harmful. The release of formaldehyde from various resins into the completed product, which frequently occurs with urea-formaldehyde bonded products, is a cause for worry.
  • Some products can expose workers to harmful chemicals when they are cut or handled in various ways.
  • When compared to equivalent solid woods, some engineered wood products, such as those intended for indoor usage, may be weaker and more susceptible to humidity-induced warping. Due to their propensity to absorb water, the majority of particle and fiber-based boards are inappropriate for outdoor use.

 

Read more: Types of woodworking hand and portable tools

Conclusion

Sheathing made of wood structural panels preserves the house’s structural toughness and enables walls to be insulated to higher R-values, creating high-strength wall systems that are affordable and convenient for contractors. That is all for this article where the following questions about wood structural panels are been discussed.

  • What is wood structural panels?
  • What are the applications of wood structural panels?
  • What are the properties of engineered wood?
  • what are the types of wood structural panels?
  • What are the benefits and limitations of engineered wood?

I hope you learned a lot from the reading, if so, kindly share with others. Thanks for reading, see you around!