Roof Trusses; A Brief History

Roof trusses are considered the most important component and key engineering system in a building. They serve a critical function and their design depends on various factors and is generally left to professionals to determine what is appropriate. Conventional trusses consist of a frame that has been fabricated from wood or steel, forming a sequence of connected triangles to produce a stable structure. This system of sequential triangles supports the decking, sheathing, and other materials of a roof.


It all started in Pompano Beach, Florida, when A. Carroll Sanford invented this system by connecting triangulated lumber with galvanized steel gusset plates. It resulted from an investigation of plywood gusset plates and the consolidation of glue, nails, screws, and staples from which trusses were developed. Its configuration has not changed over time; however, the components, lifespan, price, and safety features have been altered. When the effectiveness of this engineered system was discovered, the intent was for this invention to be patented. This move marked the beginning of the invention of the truss. Across the globe in any type of building construction, whether it is a home, apartment, or commercial building, infrastructure trusses are widely used.

In the early 1960s, prefabricated roofing trusses were developed, consisting of a multi-nail plate connection that can be easily mass-produced along with a wooden frame. Both of these components are bolted together to form the system. The design was improved to have clear-spanning to provide a larger space and more open room to cater to heavier loads. This method has been proven to be cost-effective, quick to fabricate, less labor-intensive, and less material required to manufacture.

Modern Layout

Unlike earlier construction when this structure had to be done by human labor, thanks to technological advances, the fabrication, design, and manufacturing are computerized. With the use of the computer, this structure can be easily configured into different shapes and sizes to match any type of roofing design.

Construction engineers generally design the style of the roof before deciding what type of framing must be created to support it. Engineering principles and building codes are taken into consideration as well as the type of materials, stress conditions, ceiling, wind, snow, and other types of extraordinary loads this structure may need to hold. All of this information is then entered into the computer. A printed copy of the drawing will then be produced with all the details and specifications which will become the basis of the construction project.

Quickly and easily the computer will specify the type, dimensions, wood species, lumber size, and grade of wood. Furthermore, the computer will accurately specify the gauge, size, and orientation of metal plates as well as the strength and exact placement of permanent bolting.

Truss Types

There are two types of trussing designs utilized for new construction roofing: pitched and flat. A pitched design is easily recognized by its triangular shape formed by a web and chord configuration. This is commonly seen at almost any construction site. The flat design is determined by the combination of parallel top and bottom chords. Both types have their advantages and disadvantages and the decision to use one or the other is generally based on aesthetic and structural purposes.

It is imperative to determine the types and designs of the trusses when remodeling a home so that they will suit the appearance and function of the entire system. The key advantage to using this type of system is that it is less expensive, able to be made to order, has accurate sizing, and is quick and easy to install. When bolted together in the right position, these trusses will form strong structural support.

Ordering – Specifications

It is critical to learn and specify the correct design, type, measurement, and other aspects when using a prefabricated frame. Failure to provide precise specifications can result in weak and inefficient building construction. Basic specifications include the span, type, number, overhang length, design load, end-cut, slope, overall height, and bearing width.

Any building can use trusses for the framing of its roof. These are triangularly shaped wooden or metal structures used to support the entire roofing system. This type of framing system is very common because of its many advantages in terms of structural support.