Roofing 101: What Is a Truss?

The more you know about roofing terms, the smarter your home design choices will be. Roof trusses have overtaken rafters as the most popular way to create a roof frame. And there’s a good reason why trusses have become more popular – they’re cheaper, more convenient and extremely versatile.

In this article, professional shingle roof contractor, Dynamic Roofing Concepts Inc. breaks down what exactly roof trusses are and explains some of the most common types used in order to help you get insight into what kind of roof trusses you may want to use for your roof construction project.

What Is a Roof Truss?

In structural engineering, the word “truss” describes a triangular design. Essentially, roof trusses create a roof’s frame. They determine the shape of the roof and ceiling while providing support for the roof. Trusses are pre-engineered in a factory using lightweight materials, like 2?4s and are shipped to the construction site. Trusses consist of three main parts:

1. Top chords
2. Bottom chords (also known as I-joists, or ceiling joists)
3. Webbing/posts

You will find them supporting the roofs of auditoriums, cinema halls, stadiums, railways, stations, airports and others.

The Benefit of Roof Trusses

Roof trusses have stood the test of time in construction because of the number of structural benefits they provide to homes and buildings. A roof truss is considered the most important key component in an engineering system in a building. They serve a critical function and design depends on various factors. Without roofs, buildings would be exposed to all kinds of elements, rendering them completely useless.

Different Types of Trusses based on Shape and Material

1. King Post Truss – Central vertical post used in architecture, working in tension to support a beam below from a truss apex. This truss usually spans up to eight meters, which makes it perfect for multiple types of houses, especially the smaller ones.
2. Queen Post Truss – A very reliable, simple and versatile type of roof truss where you can use at any given time. This kind of truss offers a span of around 10 meters and has a simple design which makes it perfect for a wide range of establishments.
3. Howe Truss – A kind of truss having upper and lower members, a combination of steel and wood or both. One thing that makes this truss extraordinary is that it has a very wide span, as it can cover anything from six to 30 meters.
4. Pratt Truss – The prat metal roof truss is the most popular steel truss since it is very economical. It includes vertical and diagonal members that slope down towards the center (opposite of Howe Truss).
5. Fan Truss – A simple design made out of steel. Most projects with a larger span of around 10 to 15 meters use this kind of truss.
6. North Light Roof Truss – Have a wide set of lattice girders that include support trusses. North light truss is the oldest and most economical kind of truss. These are found in industrial buildings, drawing rooms and large spaces, with a span of 20 to 30 meters.
7. Quadrangular Roof Trusses – A type of truss having parallel chords and an arrangement of web members of tension diagonals and compression verticals. It is mostly encountered in auditoriums or railway sheds.
8. Parallel Chord Roof Truss – Constructed with two chords running parallel to each other and supported by reinforcing trusses in between the top and bottom chords. This roof truss reduces the condensation problems and mold conditions since they create a vapor barrier.
9. Raised Heel Roof Truss – Provides a cost-effective way to meet more stringent energy efficiency codes and improve the energy efficiency of your building envelope. Raising the truss higher greatly simplifies attic ventilation and leaves ample room for insulation above exterior wall top plates.
10. Scissor Roof Truss – The bottom chord members cross each other, connecting to the angled top chords at a point intermediate on the top chords’ length, creating an appearance similar to an opened pair of scissors. A scissor truss provides for a vaulted ceiling in the same time frame as standard trusses.

We’ve listed out 10 of the most common roof trusses, but there are many more types on the market. From tile roofing to asphalt shingles, to vaulted ceilings and flat roofs, there is likely a truss that can help you get the job done. Roof trusses are versatile, cost-effective and convenient. Working with an experienced architect or structural engineer is the best way to guarantee that you’ll find the right trusses for your home and meet your building code requirements.

Dynamic Roofing Concepts Inc. is a leading Florida roofing company with an established reputation for quality, dependability, workmanship and professionalism. As a GAF Master Elite®-certified contractor, we specialize in several different types of roofs, so don’t hesitate to get in touch with us for inspection, repair, installation or maintenance work.

To contact us for a free estimate with no obligation on a new roof or repair, call (813) 510-1166 or fill out our online request form. We serve clients in Tampa, FL.