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.
Also, trusses, particularly triangularly shaped ones, provide strength and stability to a roof. "A triangular framework distributes loads both vertically and laterally, meaning it easily bears the weight of the roof and resists winds," says Matt Consolo, CEO and owner of Air Force Roofing in South Florida.
In this article, we break down what exactly roof trusses are and explain 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.
Key takeaways
Roof trusses are at least 30% cheaper than post-and-beam construction.
The home's style will dictate the type of truss.
What is a roof truss?
Essentially, roof trusses create a roof’s frame. "They allow designers to create long-span open floor plans while maintaining the structural integrity of the roof system, protecting occupants from the elements and outside dangers," says Jeff Akerman, strategic construction advisor at HouseCashin and a licensed architect in New York. They also 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 2x4s secured with metal plates, and are shipped to the construction site. Trusses consist of three main parts:
Top chords
Bottom chords (also known as I-joists, or ceiling joists)
Webbing/posts
Trusses are used as an alternative to rafters, or stick framing. Rafters are usually made from larger pieces of lumber, such as 2x8s or 2x10s, and require the skill of an expert carpenter to custom-build and install them directly on the job site. This makes rafters more expensive than trusses.
Other terms to know about roof trusses include:
Span – the length of the bottom chord
Pitch – the incline of the roof or top chord.
What are the advantages of roof trusses?
Roof trusses have become more popular than rafters in recent years for a few reasons. Perhaps the biggest reason trusses are more common is that they are over 30% cheaper than rafters.
They use lighter materials and are able to be produced and purchased in large quantities, driving down the price. The labor costs associated with trusses are also lower, as they don’t require the skilled labor of an expert carpenter. You can expect to spend anywhere between $50 to $450 per truss.
Also, truss designers use computer-aided design (CAD) software to design trusses. The software allows them to calculate specific loading and spacing requirements for each section of the home. When assembled, sophisticated tools allow precision cutting for uniformity and easier electrical, plumbing, and HVAC installations. And before trusses leave a plant, they are inspected to ensure they meet current building codes.
For added peace of mind, use a well-known manufacturer. "As long as you use a reputable truss manufacturer," says Consolo, "they’ll provide certifications and warranties that show their products meet or even exceed industry standards."
Another big advantage of truss systems is that they can be designed to distribute the weight of the roof onto the exterior walls of the house, not the interior walls. "The beauty of a triangular shape is it has the strength to span a large distance, with only intermediate supports," says Consolo. With few to no interior load-bearing walls, home developers can more easily create the wildly popular open-concept living spaces.
When designed correctly and under certain conditions, removing the webs from the center third of a truss does not affect its structural integrity, freeing up usable attic space. – Jeff Akerman, HouseCashin
It also makes it easier for homeowners to take out interior walls in future renovations and home improvement projects. However, to be safe, always consult with a licensed contractor or engineer before removing walls.
Plus, there are countless truss designs to create the roof framing for almost any roof style. From gable roofing, to hip roof sections, there is a truss that will meet your needs.
Types of roof trusses
Comparison of roof truss types
Type of truss | Common uses | Span |
King post | Home additions, garage construction, short-span projects | 16 to 26 feet |
Queen post | Large residential and agricultural construction | 26 to 39 feet |
Fink truss | Residential home construction | Up to 46 feet |
Attic truss | Residential projects that require an attic or additional loft living space, garages | Up to 82 feet |
Scissor truss | Residential projects that require vaulted ceilings, churches | Up to 72 feet |
Gable roof truss | Residential gable roof construction | Varies, depending on roof design |
Mono truss | Agricultural and commercial construction, carports, and room additions | 16 to 40 feet |
Gambrel truss | Residential buildings, sheds, barns, and garages | 24 to 30 feet |
Hip roof truss | Residential and commercial construction | 24 to 60 feet |
Again, there are a ton of trusses available to complete your building project. We’ve compiled a list of some of the most commonly used roof trusses for home construction.
King post truss
King post trusses are the simplest roofing truss.
King post trusses are the most basic type of truss. It uses the fewest truss members - two top chords, one bottom chord, a central vertical post called the king post, and two webbing chords.
Because king post trusses are made with few materials and a simple design, they come at a lower price point than many other trusses and are easy to construct. However, this also means that king post trusses cannot span long distances, so they are better suited for smaller-scale projects.
Queen post truss
Queen post trusses are well-suited for larger residential projects.
Queen post trusses are similar to king post trusses in that they have a simple, yet sturdy design. Instead of having one king post in the center, this type of truss will have two queen posts that are connected by a straining beam.
The additional posts in a queen post truss make them slightly more expensive than a king post truss.
The two vertical queen posts allow queen post trusses to span greater spans than king post trusses, which means they can be used for larger projects. They also provide greater strength and stability, making them suitable for larger residential buildings and agricultural structures.
Fink truss
Fink trusses are the most common truss for residential projects.
Fink trusses are the most common truss seen in residential roof construction. The webbing in fink trusses has a ‘W’ shape, giving them a great load-carrying capacity. The position of the webbing allows for some storage space and can accommodate things like water tanks if need be.
They are also considered one of the most cost-effective house trusses available because they provide strength and stability with a minimum amount of materials and can span long distances.
Attic truss
Attic trusses allow for storage space and sometimes even added living space.
One downside to many trusses is that the webbing can often limit attic space. This can be a dealbreaker for homeowners looking for additional storage or living space. Luckily, there are attic trusses, which are built to allow for attic space.
Attic trusses look similar to queen post trusses, but the two vertical posts are spaced further apart to allow for attic space. Also, the bottom chord is designed to accommodate live loads similar to floor systems. The wider the building structure is, the bigger the attic space will be. The steeper the roof pitch is, the taller the attic ceiling will be.
Also called a room-in-attic truss, this is the option used when space is needed to conceal HVAC equipment. For this reason, they are popular over garages.
Scissor truss
Scissor trusses can create vaulted cathedral ceilings.
Scissor trusses make it possible to create vaulted or cathedral ceilings. The bottom chords of scissor ceiling trusses are sloped, creating the dramatic ceiling in the room below. Scissor trusses combine the speed and convenience of using pre-engineered wood trusses, while still getting the aesthetic benefit of high ceilings.
You can install scissor trusses in one part of your home, and use other types of trusses in other areas of your home where you don’t want vaulted ceilings. What’s great is that from the outside, your roof will look uniform, even if one area has high ceilings. Technically speaking, the top chord pitch, span, and heel height determine the bottom chord pitch. But typically, the pitch for the bottom chord is half that of the top chord.
Keep in mind that scissor trusses do come at a higher cost than other types of trusses - sometimes up to 30% more than standard truss types.
Gable roof truss
Gable trusses act as the ‘bookends’ to your roof.
Gable trusses are usually used in combination with other types of trusses. The gable truss serves as the ‘end cap’ for the roof. They have two top chords meeting at a central ridge, one bottom chord, and multiple vertical posts. Gable trusses are built on each end of the roof framework to support roof sheathing. Their configuration allows for retrofitting windows or fan vents without compromising integrity.
Gable trusses will cost anywhere from 25% to 50% more than standard-style trusses.
Mono truss
Mono trusses accommodate a greater span width in agricultural buildings.
Typically used in agricultural and commercial buildings, the mono truss looks like half a truss as it only includes one pitch or side of the complete roof triangle. The upright portion of the truss rests on a center bearing. Their simple, cost-effective design allows for efficient drainage and is used as an alternative to a single truss when a long span is required. Mono trusses are also referred to as a monopitch or monoslope truss. Residential applications include carports and room additions.
Gambrel truss
A gambrel truss provides the framework on which to construct this unique roof style.
A gambrel roof is a modified gable where the sides opposite the ridge change slope partway down. This roof truss design is often associated with barns and is sometimes referred to as a Dutch roof. A gambrel roof provides additional space for an attic or upper story. A gambrel truss includes a lot of webbing to support its unique shape.
Hip roof truss
A hip roof truss provides strength and stability in high-wind areas.
Unlike a gable roof, which includes two planes that meet at the ridge line, a hip roof has four planes that meet at the top, creating a pyramid shape. This style is stronger and more aerodynamic than other roof styles. Its wind resistance and steep slopes make it suitable for areas prone to high-force winds and heavy snow loads.
Hip roofs are found in residential and commercial buildings. Because of their steep slopes, homes with hip roofs boast more attic space than other designs. Homeowners often capitalize on the added headroom by adding dormers.
Factors to consider
When building a new home or adding a room addition, several factors must be considered when choosing the type of truss to use. Of course, homeowners are rarely consulted in this process, as it largely depends on the overall home design and interior layout. Therefore, architects or design builders will choose a truss that complements the structure and contributes to a visually appealing and cohesive architectural style. To assist them in making this decision, they will consider the following key factors.
Roof type – Because the gable roof, hip roof, or gambrel roof have different rooflines, for example, they will require different trusses.
Construction budget – Some truss types cost more than others.
Span and load requirements – The room's breadth will dictate the truss's span and the type of truss that can handle the load.
Home design – The desired aesthetic and interior layout of the home will dictate the truss design. Vaulted ceilings, open concept floor plan, and livable attic space all require certain truss styles.
Cost and efficiency
Manufactured trusses are more economical and efficient than timber-framed roofs with a ridge beam and rafters. There are several reasons for this. First, not all carpenters are trained in timber-frame construction. Therefore, this style of construction requires hiring an additional crew, which adds to the cost of the project.
On the other hand, a truss system roof that uses manufactured trusses costs less to create. The roofing trusses are engineered to exact specifications and delivered to the job site. "You have a consistency that you don’t get with a traditional stick-framing method, which typically results in waste," says Consolo.
The average cost to supply and install manufactured trusses ranges from $10 to $15 per linear foot, depending on the truss style, span, and roof pitch. In comparison, the average cost to build a timber truss runs from $240 to $425 per linear foot.
Roof trusses are built to handle complex roof designs that would be difficult, if not impossible, when stick-framing. – Matt Consolo, Air Force Roofing
Roof trusses are convenient and reliable
We’ve listed out six of the most common roof trusses, but there are many more types on the market. From metal roofs 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.
Frequently asked questions (FAQs)
Truss manufacturers can purchase lumber and other materials in large quantities, which allows them to offer a completed product for less money than an individual.
While they serve the same purpose in supporting the roof, rafters are part of the roof framing that is built on-site, and trusses are manufactured in a plant and shipped to the job.
The Fink truss (W truss) is considered one of the most cost-effective trusses because it provides strength and stability using minimal materials that can span long distances.
A truss is a triangular framework that supports a building's roof by distributing the roof's load over a large span.
Carol J Alexander is a home remodeling industry expert for Fixr.com. For more than 15 years as a journalist and content marketer, her in-depth research, interviewing skills, and technical insight have ensured she provides the most accurate and current information on a given topic. Before joining the Fixr team, her personal clients included leaders in the building materials market like Behr Paint Company, CertainTeed, and Chicago Faucet, and national publications like This Old House and Real Homes.