How to Build Roof Trusses in 5 Steps

Roof trusses are sturdy, versatile, and cost-effective structures that provide a supportive framework for your roof. Wood roof trusses combine all the parts of the roof system with inexpensive, lightweight frames that are easy to build and install. You don’t even need years of training to create your own—but having carpentry experience is helpful. Read on to learn how to build roof trusses for a strong and sturdy roof. 

What Is a Roof Truss?

Roof trusses are often confused with roof rafters. Although not wrong, there’s more to the story. Roof rafters are simply the angled boards that support and provide a place to install the roof decking and other roofing materials.

Traditionally, installing rafters was just part of the overall framing of a roof. Other parts of typical roof framing are the ceiling joists, ridge boards, and collar ties, to name a few.

A set of trusses combine all of those framing parts into single units that provide the same functions as a hand-framed roof in a way that makes their construction and installation a snap, which saves both time and money, and a strong roof. Building and installing roof trusses is faster and less expensive than hand framing a roof because trusses use less lumber than traditional roof construction.

How to Prep for Building Roof Trusses 

Before building trusses, you’ll need to create your roof truss plans and obtain a building permit for your project. The permitting department of your municipality must approve your truss design to move forward. They may even require you to hire a local structural engineer to evaluate your plans, whether you’re making trusses or hand-framing your roof.

Create your truss configurations by simply drawing your plans, or use truss-design software and let your computer do the work before printing your plans and measurements. Optionally, hiring an architect in your area to design your roof is never a bad idea.

How to Build Roof Trusses

You can build wooden roof trusses using the following steps. 

Truss Building Tips

Roof trusses provide several advantages over hand framing your roof. Here are a few tips to make the experience even better. 

• Unlike fine woodworking projects, the more helpers on-site when installing roof trusses, the better.

• Your trusses will likely never get wet. However, use exterior-grade hardware for roof trusses to ensure that the metal won’t corrode if your roof suffers a leak in the future.

• If you’re installing trusses on a shed or small single-story building, you may be able to skip the crane and operator and use 2x4 lumber to build a temporary lifting tool to tip each truss onto its end and easily slide it into place. Attach a short board to a long one in the shape of a giant lowercase letter Y. Turn the truss upwards by placing the tool's junction in the truss's apex and lifting. 

• To avoid confusion and delays during installation, measure and mark the position of each truss’s connection points on the top plates before standing them up. 

• To speed installation, instead of carrying and installing one truss at a time, place all of them upside down and resting on the top plates within the structure. Then flip one up at a time, secure it, and move on to the next. 

DIY vs. Hiring a Pro

If you’re supplying the labor, you can dramatically reduce the cost of the trusses for your project. Expect to pay between $1.50 and $4.50 per square foot on average for materials. That's the cost of the trusses only, though, and it doesn't include any additional roof replacement costs or labor. 

Although building trusses is an intermediate-level DIY project, installing them can be tricky, especially on irregular roofs or second stories. 

If you’re uncomfortable installing roof trusses or the safety factor is just too risky, a local roofer can help. Labor typically costs between $25 and $75 per hour to install factory-built trusses. Depending on their complexity, pre-made trusses cost $60 to $500 per piece.