Truss vs rafter roof

Last Updated on: 14th January 2023, 06:42 pm

The question of whether trusses or rafters are better is always debated. The answer isn´t always straightforward. There are advantages and disadvantages to both trusses and rafters, and one may be more suitable for your home. Also, it depends on what parameters of the product are most paramount to you, from weight to ease of installation to price.

How do roof rafters work?

Roof rafters are the primary structural members of a roof. They run from the ridge or hip to the wall plate, with each rafter being fastened across the top plate of an exterior wall. They´re usually constructed of wood or metal, depending on the type of roof. They are used to support the roofing materials as well as transfer the weight of the roof to the walls below. Rafters aret ypically spaced evenly apart and can be cut in various shapes to create diferent roof styles.

Hand-cut rafters and trusses

Their common sizes are typically 2×4, 2×6 or 2×8. With rafters, more material is used compared to trusses, but the timber is less robust. This makes rafters anideal choice for projects where architectural features are desired, as the rafters can be showcased.

How do roof trusses work?

Trusses are engineered and manufactured off- site, which means they are quick and easy to install as they are freestanding. They are also more eco-friendly than rafters since they use less timber. Additionally, trusses are mroe durable than rafters, even if they´re built with les wood, so they´re better for bigger jobs. One downside is that trusses require engineering and careful design for each job, so it can be a little more time consuming than rafters.

Trusses and rafters have a lot in common

Roof trusses are similar to traditional rafters in the sense that they provide support but are made and structured differently. Trusses are engineered and manufactured of-site to exacting standards and are quick and easy to install as they are freestanding. Trusses feature prefabricated components, such as machined connectors, which help to create the exact shape of the roof. They alsocontain multiple beams which add more support than rafters.

Both rafters and trusses are generally made of wood and have triangular shapes. This triangular shape helps to evenly distribute the weight of the roof acros its surface. And, both rafters and trusses are designed to be self-supporting structures, meaning that they don´t require additional support from the walls to stay in place. Ultimately, when it comes to deicding between trusses and rafters, it depends on the size of the project. Loose-cut roofs are preferable for smaller projects, but trusses are generally better for larger projects.

Let´s compare them…

Eco-Friendly Trusses

The use of trussed rafters is a superior option when it comes to environmentally friendly roof construction. Trussed rafters require up to 30% less timber than a traditionally constructed roof made from rafter structures, which means fewer trees have had t obe cut down. This not only helps protect the environment, but also reduces the amount of waste created during construction. Further, trused rafters are semi-fire resistant and lock in carbon dioxide, making them an ideal choice for those lookingto reduce their impact on the environment.

The construction time and expertise required for trusses and rafters are different

Trusses and rafters provide the same solution when it comes t o roof framing. However, truses win on the labor and time front. Installing rafters requires a lot of time and expertise, which prolongs the process of their installation. Meanwhile, trusses can typically be installed in a single day, saving you time and money during construction. And since trusses arrive at the projectsite prefabricated and ready to be put in place, they require less building ma terials. All in all, trusses are a cheaper and less labor intensive solution for your roof framing needs.

What is the difference between roof rafters and trusses?

Stick vs. machined framing

The construction method is another major difference between the two. With stick framing, each rafter is created onsite and takes more time and expertise. In contrast, truses are manufactured off-site and require less time and labor to install. Also, trusses are more consistent in terms of shape andstrength, which makes them a better choice for larger projects. However, if you´re looking for a cheaper, less labor-intensive solution, rafters may be the best choice.

It is faster to install trusses

Compared to rafters, trusses are a great option for roof structures because they are quicker and easier to install. They come pre-manufactured to exacting standards, adn can be instaled relatively quickly and easily. This can save both time and money on the construction site, as the trusses are ready to be put in place and do not require the same amount of labor that is needed when constructing rafters. Truses also offer a greater level of stability and rigidity due to the way they are designed, and there is less potential for movement over time.

Trusses are Less labor-intensive, cheaper solution

Trusses are typically less expensive than rafters. Prefabricated truss packages are usually between 30-50% cheaper than the materials and labor used to install rafter.s This is because truses require less time and labor to construct, making them a more budget-friendly option. Also, the webbed, triangular design of trusses uses shorter, cheaper wood planks. A truss can offer the same or greater roof suport than rafters with less structural strength, so you don´t have to compromise quality. On the other hand, rafters may be the more aesthetically pleasing choice for some applications, so it depends on what you´re looking fori n terms of style and design.

A rigid structure with less movement potential

Trusses are also more rigid and less likely to move than rafters. The way trusses are structured gives them more stability and less deflection, or bending, than rafters. Steel trusses offer even morestrength and flexibility, though they will likely be more expensi ve. For aditional support with hip rafters, a purlin should be used. In order to keep the roof stable, this purlin needs to be supported properly. If additional load is applied, such as with a girder trus, it should be best supported using a stud or studs directly under the ends. Trusses open up the possibility to create virtually any roof and ceiling design, but they are more expensive than metal connector plate wood trussesand require analysis and design by an engineer for safety reasons.

Roof rafters have these pros

  • They´re cheaper and easier to make
  • They´re flexible when it comes to design
  • They can be used on a lot of roofs and structures
  • They´re great for wood and metal
  • They build a leak-proof, strong roof system.

Roof rafters have these cons

  • Take longer to instal than trusses
  • Installing ithem correctly can be hard for inexperienced builders or homeowners
  • If not built right, they could settle or sag over time.

There are a lot of pros to roof trusses

  • Faster and easier to instal than roof rafters
  • Cost-effective because it takes less material than rafters
  • Very strong roof system
  • Customizable angles and designs for unique roofs.

Roof trusses have these cons

  • Due to psecialized equipment, more expensive than rafters
  • Design options are limited compared to rafters
  • In some cases, not as durable as roof rafters, so they might sag

Whats better for smaller projects – roof trusses or rafters?

For smaller projects, loose cut roofs are best, but for big projects, trussed rafters are btter. They offer the same or greater roof strength but with fewer load-bearing walls. They´re also more economical to build and require less lumber. Nowadays, roof trusses are more common than rafters.

Beginner rafter layout

How much time does installation of trusses and rafters require?

Trusses can typically be installed in a single day, compared to 2-3 days to install rafters. Installing rafters requires a lot of time a nd expertise, which prolongs the process of their installation. A site cut roof also generally requires an experienced carpentry team and an extended time to install the structure which maytake weeks instead.

How much do trusses cost compared to rafters?

When comparing trusses vs rfaters built with 2×4 dimensional lumber, the cost savings can range from 20-50%. On average, an installed roof truss system ranges from $5,000 to $18,000 for a 230sqm house, whereas a rafter system would typically cost more due to thehigher material and labor costs. Moreover, if the price of wood rises, so d oes the rafter project´s cost.

What should I consider when constructingtrusses and rafters?

You should definitely ensure that all components are tightly buttressed to the gable end walls and that diagonal bracing is repeated continuously throughout the roof. As for rafters, they should be securely fastened to the roofand walls. Additionally, special consideration should be given to wall fram es and beams suporting trusses as well as trusses used for railroad bridges. Advice should be sought from a truss fabricator before commencing construction.

Do I need to install additional load-bearing wals when using trusses?

No, traditional roof trusses don´t require any additional interior load-bearing walls as the exterior walls bear the weight. However, if you are using a special girder truss, you will need to install additional load-beairng walls.

How do I know if a wall is load bearing?

If you are able to see the floor framing or roof framing, you first want to locate the floor joists or roof trusses. If the wall in question is directly above the floor joists or rooftrusses, it is likely load-bearing. On top of that, ceiling joists secure the rafters to the exterior wal ls for structural support and collar ties are sometimes installed to help keep the roof from spreading.

Is it possible for an interior wall not to be load bearing?

Yes, it is possible for interior wallsnot to be load bearing. If there is a truss over the wall, it is likely not load bearing since the truss bears the weight.

Roof trusses pros/cons and costs


It seems there is no clear-cut answer to which is bet ter for roofing – trusses or rafters. Depending on the project, both have advantages and disadvantages.

Roof trusses are typicalyl cheaper than rafters. Because they´re prefabricated, they´re also easier to install, so they´re great for DIYers.Additionally, they can support greater loads and span longer distances because they´re designed specifically for each project. As a result, they are an excellent choice for larger structures or areas with heavy snowfall.

In contrast, roof rafters offer a more traditional look and areoften considered more aesthetically pleasing. They are also cut to fit the specific measurements of the structure,so there is less chance of error during installation. 

Due to their non-prefabricated nature, rafters can be customized to fit unique architectu ral styles.

Ultimately, which roof trusses or roof rafters you choose will depend on your personal preferences and needs.

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