Everything you need to know about floor and roof wood trusses

What are wood trusses? Wood trusses are structural frameworks manufactured from wood, designed to support various elements of a building, such as roofs and floors. Their composition typically includes triangular units, which are interconnected to one another using wood or metal gussets to create a stable and sturdy framework. The extensive use of wood trusses in modern construction has lowered the cots for both roof and floor elements of a building. A key feature of these trusses is their ability to evenly distribute the weight of the structure they support, ensuring structural strength and stability. These characteristics make wood trusses an indispensable part of building construction.

Wood trusses are typically constructed off-site in an under-roof-controlled environment. This process ensures precision and quality before they are transported to the actual construction site for assembly. Each truss is professionally designed using computer software to meet specific load-bearing requirements and engineered to provide optimal structural support while complying with local building codes. Typically built using construction grade spruce, wood trusses can be customized to suit the unique demands and architectural requirements of individual projects, allowing for creative construction solutions, such as a vaulted ceiling, for example. This adaptability, combined with their structural advantages, make wood trusses the cost-efficient choice for a wide range of construction projects.

Roof trusses

Roof trusses play a pivotal role in modern building construction, offering essential support to various roof styles. These trusses are made up of an intricate arrangement of vertical, horizontal, and diagonal pieces of wood, meticulously engineered to bear the roof's weight and efficiently transfer it to the building's walls and down through to the foundation. Their structural design not only provides snow load support but also ensures the stability and durability of the roof for several decades. They are versatile enough to accommodate a range of roofing materials and styles, from traditional pitched roofs to more complex designs like mansard or hip roofs.

Floor trusses

Floor trusses are a critical structural component in modern wood frame buildings, especially in multi-story buildings where they play a vital role in supporting and distributing floor weight. Unlike traditional joists, floor trusses are specifically engineered for long floor spans that may require additional support. Their flat truss design, which includes a web of interconnected beams, allows them to cover these large spans effectively and efficiently, eliminating the need for under floor beams and support columns. This feature allows floor trusses to be incorporated into complex building designs, providing architects and engineers greater design flexibility. By using floor trusses, it's possible to create open, spacious interiors without compromising structural integrity. This flexibility not only enhances the aesthetic appeal of a space but also provides many options for interior design.

King post truss

The king post truss is one of the simplest and earliest wood truss designs. This truss design is characterized by a central vertical member, known as the king post, which supports the horizontal beam, commonly referred to as the tie beam. Flanking the king post are two inclined members, the rafters, that extend downwards to the structure's base. The king post truss is typically used for smaller-scale structures like sheds, garages, and residential projects due to this straightforward design and speedy, stand up of construction.

Queen post truss

The queen post truss is similar to the king post truss, but instead of a single vertical member, it has two vertical members (the queen posts) that support the horizontal beam and the rafters. Queen post trusses are commonly used in larger structures such as houses and barns.

Fink truss

The Fink truss, the most used type of wood truss, is popular due to its broad range of applications in the construction industry. This truss is composed of multiple triangular units, meticulously interconnected to form a strong and stable framework capable of supporting significant snow loads. The geometric configuration of the Fink truss, featuring a repeating pattern of internal webs and struts, contributes to its high strength-to-weight ratio. This design efficiently distributes the load across the structure, enhancing its snow load-bearing capacity. A key advantage of the Fink truss lies in its simplicity and low cost, which makes it a particularly popular choice in both residential and commercial construction projects. Its versatility allows it to be tailored to a variety of roof shapes, pitches and sizes, catering to a diverse range of architectural needs.

Howe truss

The Howe truss is similar to the fink truss, but the diagonal members are oriented in the opposite direction. This design provides additional stability and strength, making Howe trusses ideal for longer spans and heavier loads.

Pratt truss

The pratt truss is characterized by its diagonal members, which are oriented to slope toward the center of the truss, a design that significantly enhances its load-bearing capacity and stability. The Pratt truss's design effectively counters the forces of tension and compression, making it particularly suitable for applications where heavy loads are a consideration, such as in bridges and large industrial buildings. The arrangement of the truss's components allows for longer spans and heavier loads without compromising structural integrity. This makes the Pratt truss an ideal choice for projects requiring a robust framework capable of withstanding significant stress and strain from windblow and vehicular traffic.

Scissor truss

The scissor truss is easily identifiable by its sloping bottom chords, which crisscross each other in the center, mirroring the workings of a pair of scissors. This special configuration not only provides a striking visual element but also serves a practical purpose. The scissor truss design facilitates the creation of vaulted or cathedral ceilings, offering an expansive and airy feel to the interior spaces. This feature is particularly advantageous in buildings like churches, auditoriums, or residential spaces like living rooms where a sense of openness and grandeur is desired. The structural integrity of the scissor truss, coupled with its aesthetic appeal, makes it a sought-after choice for projects that require both an impressive visual impact and reliable support for large, open spaces.

Gambrel truss

The gambrel truss, often seen gracing the roofs of barns and agricultural out buildings, is a distinct and practical truss design that has several advantages. It is characterized by its unique, symmetrical profile, featuring two different sloping sections on each side of the roof. This design resembles the classic barn roof style, providing not only an aesthetic reminiscent of traditional agricultural architecture but also functional benefits. The upper slope of the gambrel truss is usually steeper than the lower one, creating additional vertical space in the upper part of the structure. This extra headroom is particularly advantageous in barns and storage buildings, as it maximizes the usable space under the roof, allowing for more efficient storage or even additional living quarters. The gambrel truss's design also contributes to efficient water and snow shedding, making it suitable for regions with heavy rain or snowfall.

Attic truss

Attic trusses enhance the utility of attic spaces in residential buildings. These trusses are engineered with a raised heel, a distinctive feature that significantly elevates the roofline at the eaves. This innovation creates a larger, more accessible, and functional space in the attic area, effectively transforming what might otherwise be an underutilized or cramped space into a valuable asset. Whether it's for additional living quarters, a home office, a recreational area, or simply for extra storage, attic trusses provide a practical solution for maximizing the available space within a home's existing footprint. Their use in residential construction is especially valuable when expanding the building's footprint is either impractical or impossible. By utilizing the space under the roof, attic trusses offer homeowners an efficient way to increase their living or storage space without the need for costly and extensive renovations or additions.

Mono truss

Mono trusses are designed to span a single slope of a roof. They are often used in residential construction for roofs with a single slope or in combination with other truss types to create complex roof designs.

Fan truss

As the name suggests, fan trusses feature a fan-like design with diagonal members radiating from a central point. They are commonly used in architectural designs to create unique and eye-catching roof structures.

Northlight truss

Northlight trusses are characterized by a series of north-facing windows or skylights. They are often used in industrial buildings and warehouses to provide natural lighting and ventilation.

Bowstring truss

Bowstring trusses, with their distinct and graceful curved design, offer an architectural solution well-suited to large, open spaces that require clear spans, such as gymnasiums, hockey rinks, auditoriums, and industrial buildings. The curvature of a bowstring truss, reminiscent of a drawn bow, allows it to span wide areas without the need for internal supports or columns, thus providing unobstructed, expansive 100 to 1,000 foot wide interiors. This feature is particularly beneficial in settings where open space is a priority, such as in sports facilities or assembly halls, where freedom of movement and versatility of space are essential. The bowstring design not only optimizes the structural efficiency, distributing heavy rain or snow loads evenly across the curve, but also adds an aesthetic dimension, lending a sense of elegance and fluidity to the architectural form. The ability of bowstring trusses to cover large areas with minimal material use also makes them a cost-effective option for projects requiring large, open-plan spaces.

Warren truss

Warren trusses are designed to provide maximum strength and stability. They feature a series of diagonal members that form equilateral triangles, creating a strong and efficient truss structure.

Polynesian truss

Polynesian trusses are a unique type of wood truss that is commonly used in Polynesian-style buildings. They feature a series of curved members that create a distinctive and aesthetically pleasing roof structure.

Mansard truss

Mansard trusses are often used in buildings with mansard roofs, which have two slopes on each side. They are designed to provide additional living or storage space in the upper part of the building.

Flat truss

Flat trusses are used in roofs with a flat or low slope. They provide a simple and cost-effective solution for structures that do not require a traditional pitched roof.

Triple fink truss

Triple fink trusses are similar to fink trusses but feature three sets of diagonal members for added strength and stability. They are commonly used in commercial buildings and large-span structures.

Wood trusses offer a cost-effective and efficient solution for structural support in buildings. They are designed to distribute the weight evenly, providing a strong and stable framework. Whether it's a residential house, a commercial building, or an industrial warehouse, wood trusses play a crucial role in ensuring the structural integrity of the construction.

Article posted, Dec 25