A support structure for a steel building kit can come in several different styles. As with most steel building kit companies, Simpson Steel Building Company sells a type of rigid structure (I-beam) or a hollow tubular steel building structure. One of the most defining characteristics of rigid frame metal buildings is its infrastructure of I-beam frames.
In addition to rigid frames, Simpson Steel has also developed and patented a steel truss design to compete with wooden structure pole barns. Our steel truss is shaped much like a wooden truss with a bottom chord, but the main exception is that all of the members of the truss are steel. This unique design allows for a significant economical advantage. Because our design is unique to us, we often receive several questions in regard to the differences between our patented steel truss frame design and rigid frame metal buildings. Here are some of the most common questions we receive.
Commonly Asked Questions
Q: Are the rigid frame designed and truss frame designed buildings essentially the same?
A: Absolutely. All components other than the frames are pretty much identical, including the purlins, girts, angles, sheeting, etc. The layout of the building and frame spacing would also be similar normally.
Q: Are we talking about the building trusses you frequently see that will essentially replace a beam in a structure?
A: No. The truss frame is essentially a large triangular-shaped structure with cross members that are constructed from red iron cees bolted back to back through steel plates. The structure is composed of 10” x 3-1/2” cees for the rafters and they are 12-gauge thickness. This is often confused with the scissor truss type beams that are built from parallel angles that have alternating rods placed in a diagonal between the two angles – then these are used in place of beams such as I-beams, etc. They do not have the same strength of design as the triangular roof support system that a Simpson steel truss provides.
Many of our competitors will tell you that the trusses are not as strong or well-designed as the rigid frames, but they are referencing these scissor truss styles, and so from that standpoint they are correct. That said, very few are familiar with Simpson’s patented truss, which can meet or exceed the strengths for rigid frame designs at a much more economical cost.
Q: What is the difference between the steel we use on our steel truss buildings versus the steel used on rigid frame metal buildings?
A: The answer is that the type of steel used in both buildings is the same! Both are red iron (which simply means red primer coated steel) steel building structures. However, in a rigid frame system, the frame will be composed of I-beam style supports that require the use of much more steel than truss structures – this is because the support in a rigid structure comes from the thickness of the steel. In steel truss structures, the support comes from the patented truss design, meaning much less steel is used for truss structures. This makes the price significantly less than rigid or I-beam structures.
Q: Which building type is less expensive?
A: Steel truss structures, when applicable, are almost always less expensive. A truss structure uses less steel than rigid frames to provide the same level of strength and support, which leads to a more economical price.
Q: We want an open span building. Is the steel truss structure open span just like the rigid structure?
A: Yes! Steel truss structures are open span throughout the building. They do not have any interior columns. One slight difference is that there will be a bottom chord that runs horizontally across the building where each truss is located and this beam will be a little over 1-1/2’ below the eave height, as the structure sits below the roof. Underneath that, the entire building is clear span.
Q: Will a truss structure meet my snow or wind load requirements?
A: Yes! The steel truss structures provide equal support as rigid structures to meet snow and wind load requirements for all areas. The difference is that the strength of steel truss buildings comes from the trusses rather than the thickness of the steel in rigid frame metal buildings. If snow load requirements are higher than normal, additional trusses would be included in the design, as opposed to just adding thickness to the steel in a rigid frame.
Q: Are the steel truss buildings easy to assemble?
A: In terms of assembling steel building kits, the steel truss structure is one of the easier types of building kits to put together. It does require a few more bolts than a rigid structure but is still simple to erect. It is a completely bolt-together building. A crane is normally required to lift the rigid frames into place in most cases. In a truss building, a truss can be assembled on the ground and then lifted into place with a forklift, tractor with forks, skid steer, etc.
Q: Do I need to know how to weld or have a crane to assemble a steel truss structure?
A: No! Steel truss building structures are completely bolt-together buildings, no welding necessary! You also will not need a crane for assembly, which will be required for the rigid frame design. The trusses will be built on the ground and you will need a forklift or bobcat to lift it on top of the columns where it will be bolted into place. A crane is required for rigid frame construction, which is a very expensive component of the cost to erect the building.
Q: I’ve heard most rigid frames or I-beam structures have about 8-12-week lead time. What is your lead time for a steel truss structure?
A: Steel truss structures have a much shorter lead time than I-beam or Rigid frame structures. The total turnaround time for a steel truss structure is generally about half that of a rigid frame system, normally around 4-6 weeks. Once a deposit has been placed, we will have your plans and drawings to you in about one to two and a half weeks depending on the amount of engineering your county requires. At that point, if you’d like us to fabricate and deliver immediately, we will have the building to you within approximately 2 and a half weeks. These time frames do not include any time for the customer to complete the permit process with a permit authority, but fabrication can take place any time after the plans are drafted.
Q: Does the freight cost the same in a steel truss structure versus a rigid structure?
A: No! Steel truss structures are significantly lighter so the freight for them costs less than a rigid structure. This is another reason steel truss building pricing is so much more economical! All pricing Simpson Steel Buildings provides already includes the freight for our buildings.
Q: Are there any limitations for the steel truss structure?
A: Yes, there are a couple. Steel truss structures do have a maximum width of 50’ on gable ends and a maximum height of 18’ tall. They can be any length you need them on the sides, however. Extremely heavy snow loads can pose a problem as well. For a truss structure to handle very large snow loads (70+ pounds), we need to add more trusses. This puts more columns down the sides which can eliminate certain operational functions inside the building because the size of overhead door openings would be restricted. In this case, Simpson Steel Buildings will recommend a rigid structure since the functionality may be limited with a steel truss frame design and the cost differential will be much closer between the two systems.
The Bottom Line
Ultimately, a steel truss frame system can provide the same or better strengths, functionality, etc. as rigid frame metal buildings, but usually at a much more economical price. When you are looking to purchase a building, make sure you check out the Simpson Steel Building patented truss frame design, where you will get the most bang for your buck, along with the best customer service in the industry.