Floor Trusses vs Floor Joists: What Builders Need to Know Before Choosing

There are various structural components that are necessary when building flooring of any kind. Trusses and joists are two of the most common structural pieces that support flooring. Knowing which to use in your next project can help you to create the right kind of floor with ease. There are pros and cons to both kinds of support structures, and we will go over those different factors in this guide.

When the choice of floor trusses vs floor joists comes up, you should be prepared to answer which one of these two structural components is right for the job. Knowing more about each of these flooring support options can help you to build a home or business location that will stand the test of time. Longevity and efficiency go hand-in-hand as considerations in construction projects. You will want to access both perks as you are choosing  between joists and trusses.

What is a Floor Truss?

A floor truss is an open-web structure. These components for flooring installations are typically made of wood, steel, or a combination of both materials. The open webbing that is part of the design removes the need to drill or notch. This saves time, but also reduces the risk of structural issues.

Pre-fabricated floor trusses are the most common since they are faster to install and save time. If you have a truly unique construction project that you are working on, pre-fabrication might not be ideal for your use case.

Floor trusses are different from joists because they are built using a triangulated framework. This distributes loads far more efficiently and makes sure that the floor span that uses them is correctly reinforced for longevity. Some truss styles will also include cantilevers that extend past the edge of the floor for things like balconies, ductwork, or façade surfaces.

What is a Joist?

A floor joist is a horizontal component used for reinforcing floors in a home or office space. Joists spread out the load on the floor so that the floor isn’t damaged over time. Joists are almost always placed 16 inches apart, parallel to one another. This is what the subflooring is nailed to, and then finished flooring surfaces are placed over this subfloor level.

Joists are usually made of wood and metal. Engineered joists are quite common in large buildings since they are far more durable than wood joists. As with trusses, these components are often ore-fabricated and then delivered to your construction site to be installed.

Floor Trusses vs Joists

Floor trusses are used in cases where spans that are very large need to be covered. In most cases, this will be a span of 40 or more feet. Joists are often utilized for span lengths that are around 20-30 feet in length.

Trusses have an open web design, which allows you to run HVAC and electrical components through the gaps in the trusses. Joists are usually solid, which means that holes have to be carefully created for these items to have a place to rest when they need to run under the floor.

Trusses are often more expensive upfront because there is more engineering and manufacturing that goes into making them. Joists are usually less costly because they are more widely available and they are simple to design.

The installation of trusses includes getting custom trusses made. If there are issues with the measurements or complications that come up during the installation job, this might cause added costs and stress. However, custom spaces can be much easier to build in when you have trusses on your side.

Joists are often easier to work with during the installation process as they can be trimmed down or altered on-site as needed.

As a rule, floor trusses will be better for wide open floor plans in spaces with limited load-bearing walls. This is the right choice if you want a squeak-free floor. These supports can withstand more significant weight as well, which can be a big deal for specific use cases.

Floor joists are better for those with smaller budgets and in buildings with standard spans. You might also opt for floor joists if you are looking to have flexibility for structural changes on the fly. Joists are far more likely to squeak, and they might also fail if they are placed under a lot of tension over time.

Maintenance for Joists and Trusses

Floor trusses are unlikely to sag or warp over time. This is because of their design. They are made for long-term stability, even when supporting large sections of floor in open spaces. Floor joists are also quite long-lasting.

You will be directed by home inspectors and construction experts to check for things like rot, insect damage, and moisture build-up for both kinds of floor supports. Noticing problems early can make all the difference in the longevity of a building. If you are not familiar with the process of checking on these common issues, you can hire a team to come and take a look at least once a year.

Choosing Between Floor Trusses and Joists Can Be Very Straightforward

If you know what joists and trusses are both good for, you will be able to tell when each of them is needed for a construction project. They serve different functions, but can both be the right choice depending on the kind of structure that you are building. Be sure as well that you think about moisture conditions, electrical, and HVAC that need to be run through your truss or joint space, and all of the other details of your build, before you make your final selection.

If you are a homeowner who is just trying to stay informed as a remodel or a new construction project is being done on your behalf, this information can be highly important to know. The more you know about the work that is being done on your property, the better. Floor joists and floor trusses are both ideal ways to correctly support the flooring in any construction project. All you need to do is select the proper fit for each kind of space.