As a structural engineer and designer, your goal is to create plans that minimize rework with
builders, trade professionals, and suppliers. One effective strategy to achieve this is to embrace
innovative off-site construction methods, such as designing for engineered components like
Open Web Floor Trusses (OWFT) from the outset. By fostering upfront collaboration, you can
streamline the construction process, enhancing efficiency for everyone involved in the project.
This approach allows you to reduce revisions, accelerate build times, and lower costs.
Consider the way roofs are built in residential construction. Before the 1950s, roofs were framed
using the “stick-built” method, toe-nailed together piece by piece on the job site. However, the
invention of the gang-nail plate transitioned roof construction to trusses, which became the
standard (and remain so) due to their strength and speed. In fact, the vast majority of new
homes in the US are now built with roof trusses—nearly 70%. It’s hard to imagine reverting to
the traditional roof framing approach at this point. Yet, when it comes to other critical framing
structures like floors, many new homes still rely on the stick-built method.
Reliance on traditional practices may be comfortable, but designing for efficiency can yield
significant benefits—especially cost savings and shorter cycle times. Designers and builders
who continue to rely exclusively on dimensional lumber or engineered wood products (EWP)
may be missing out on these advantages. Just as roof trusses revolutionized roofing,
incorporating floor trusses in the design phase can unlock new possibilities and benefits. To
paraphrase Henry Ford, if you do what you’ve always done, you’ll get what you’ve already got.
So, let’s take a look at what OWFT can get you.
Benefits of Open Web Floor Trusses
Open web floor trusses are an ideal structural system for light-framed timber structures—
including multi-dwelling, single-family attached, and single-family homes—due to their inherent
design flexibilities, optimized construction advantages, and exceptional strength. Each floor
truss is uniquely designed and engineered to meet the specifics of the project at hand.
Open web floor trusses offer significant advantages, including faster and safer on-site
installation, efficient mechanical, electrical, and plumbing (MEP) installations, and additional
opportunities for reduced material costs.
Costs Savings & Reduced Waste
Open Web Floor Trusses offer the strength for wider spacing, which allows for 25% less
material compared to traditional floors. This not only saves your builder-customers money, it
also saves them time because there are fewer trusses to install. By examining floors as an
overall system, additional areas where unnecessary materials can be eliminated can be
identified as well.
Let’s look at a quick comparison for a single-family structure where the builder saved over $830
per home using floor trusses.
Shorter Cycle Times + Open Spaces
Traditional floors require drilling through joists or adding bulkheads to accommodate MEP
installations. This can lead to mistakes and hinder the available ceiling space. In contrast, Open
Web Floor Trusses feature open chases for pipes, wires, and ducts, streamlining installation
and preventing costly drilling errors in structural members. Additionally, their design ensures
that finished spaces are open spaces, appealing to buyers seeking rooms with fewer beams,
posts, and bearing walls. Trusses can also help avoid the need for soffits. Here’s an example.
Pollard Properties in Wright City, Missouri, used the Posi-Strut® Floor Truss System in their
recent townhome development. The system's longer spans at shallower depths allowed Pollard
to create nine-foot ceilings without soffits or beams—all with an affordable product. Pollard's
trade partners also benefited; the system's precisely measured trusses allowed framers to avoid
cutting each joist, and the open webs allowed electricians to pull wire in half the time.
Opening New Possibilities
Ready to Spec: Instantly Confirm Floor Truss Viability
Engineers and architects can use a free web tool—MiTek® Truss Validator™—to validate the
feasibility of floor trusses with confidence. The MiTek Truss Validator is the only tool that
provides feasibility guidance as a starting point for your floor truss designs. By selecting
parameters such as span, depth, spacing, and a few others, you will receive an immediate pass
or fail result, along with a downloadable feasibility report.
Optimize Building with Collaborative Design
Collaborating early with your truss fabricator or component manufacturer allows you to not only
produce the floor truss system specified for your project but also design it in ways that create
value for your builder and the buyer. If you’re looking for the right truss fabricator partner, find a
MiTek-powered component manufacturer near you or email a MiTek Design Engagement
Consultant at designengagement@mii.com.
Whether you’re specifying a floor truss system, structural connectors, or lateral systems, a
collaborative design and building specifications process ensures the most efficient downstream
solution on the jobsite.
Ready to get started?