The shift from traditional stick-framed (rafter) roofs to engineered roof trusses has been one of the most significant advancements in modern homebuilding. Nationwide, over 70% of new single-family homes are built using roof trusses, either entirely or in hybrid systems that combine trusses and rafters.

When designing a floor system, builders and contractors must choose between three primary options: dimensional lumber, I-joists, and floor trusses. Each system has its own advantages, cost considerations, and best-use cases, making it critical to understand when and why to use each one.

In Colorado, the shift toward engineered wood products (I-joists and floor trusses) has accelerated due to the demand for longer spans, better material stability, and efficient mechanical coordination. Below, we’ll compare these three floor systems, outline their strengths and weaknesses, and help you determine the best choice for your next project.