In today’s light-frame construction market, wood web floor trusses are commonly used in many multifamily projects. Builders, structural engineers, and general contractors often view wood web trusses as the default floor system for projects requiring 18 inches or greater depth.
However, for projects with depths of 16 inches or less, the use of wood web trusses declines, and more traditional framing materials, such as I-joists or sawn lumber, are typically chosen.
The shift is due to multiple factors, including the ease of specification and lower cost per foot, typically found with these materials. Additionally, as wood web trusses become shallower, the joint between the metal connector plate and web patterns occupies more critical space between the chords and webs. This can lead to complications or collisions when utility lines need to pass through, as there is simply less space for these runs.
Fortunately, many of these headaches can be avoided with proper utility coordination and Building Information Modeling (BIM). For example, a chase can be designed in specific areas of the truss, allowing optimal use of the space between the chords. However, without early planning, this space can fill up quickly with trunk lines or, more often, with whichever trade shows up first, especially in single-family homes where early utility coordination is less prevalent. As a result, builders tend to choose I-joists or sawn lumber at these shallow depths, requiring soffits or dropped ceilings to conceal these elements. This approach adds additional costs for the necessary materials and requires extra work for the framer and drywaller.
While some component manufacturers have successfully promoted wood trusses at shallow depths or encouraged the use of deeper floor systems, there remains an untapped market for most component manufacturers to provide an open web solution for the shallow depth market.
Fred Johnson, Project Manager at Reno Truss, and his team have identified an effective engineered solution to address this gap for their clients: the MiTek® Posi-Strut® metal webbing system, which offers lightweight construction and high performance.
Recently, I sat down with Fred to hear his perspective on what has made the Posi-Strut a valuable addition to Reno’s offerings.
How and Why Reno Truss Switched to Posi-Strut
Reno Truss has been building wood web trusses for a long time, so what prompted you to consider adding Posi-Strut to your offerings?
Actually, we have been supplying metal web trusses for a long time. We originally started with the SpaceJoist system, and when they exited the market, we switched to the MiTek Posi-Strut system. We began with SpaceJoist before we had a floor machine because they came premade. After we got a floor machine, we started manufacturing metal web trusses with the Posi-Strut system, which allowed us to control lumber quality and design, leading to a better truss.
Have there been specific projects where the Posi-Strut system is the best choice?
In our market, the best application for the Posi-Strut web is in multi-family construction with top chord bearing. With the top chord bearings, we can significantly cut costs by eliminating the need for rim material and hangers. Additionally, the reaction limits with metal webs are better than with a single top chord. We’ve also had great success with hotels, some success with track builders, and several one-off custom homebuilders.
How did the market react when you started offering Posi-Strut?
Once a framer uses them, they realize the benefits. At first, they can be a hard sell, but after completing their first job, they appreciate their lightness compared to wood web floor trusses and their stiffness compared to I-joist. One guy can handle the joist when laying them out, which saves time and money for the framer. With I-joists laid flat, they can become flimsy, and it takes at least two guys to keep them straight, whereas a Posi-Strut is stiffer and lighter, making installation easier.
What barriers did you have to overcome?
Like any new product entering the market, there was a lack of knowledge. It took a lot of word-of-mouth promotion and getting in front of engineers to show off the product. Once the engineers were on board with the specifications and had spoken with their clients, we worked with the framers to ensure they were prepared for the installations.
What pricing comparisons did you see between Posi-Strut, wood webs, and I-joists of the same depth?
This is a tough question because they aren’t apples to apples. I-joists come in many series, but when comparing based on strengths, Posi-Struts come out about even. Now, when you factor in the savings a framer gets from labor, favorable fire ratings, and no dropped ceilings for HVAC—plus no hole cutting—the savings start to stack up. Right now, compared to wood trusses, Posi-Struts tend to be slightly higher in material costs. The benefits materialize for the component manufacturer in terms of labor savings and the speed at which we can build over wood web trusses.
How has Posi-Strut affected your production numbers?
After 24 years in the metal web market, we have proven time and again that we use 50% fewer man-hours with the Posi-Strut system than with wood web trusses.
What advice would you give to a component manufacturer considering adding Posi-Strut to their offerings?
Be dedicated to the product. It will build slowly at first, but as word spreads or it’s used in local projects, more customers will ask for it. I would also add: don’t be afraid to lean into the advantages of Posi-Struts over I-joists, like the fire rating and open web capabilities.
Adding Posi-Strut to Your Lineup
As Fred mentioned, the Posi-Strut metal webbing system has become a staple in Reno Truss’s product lineup. It offers many advantages over traditional wood webs in shallow depth applications and stacks up favorably when compared with I-joists, too. Especially if you’ve been considering expanding your product offerings, you need to consider the benefits that this system can provide.
When you’re interested in learning more about Posi-Strut and discussing how to incorporate it into your offerings and market, please contact your MiTek Sales Representative or reach out to me at skeller@mii.com.