Engineered Pole Barns: What You Need to Know

Here at Lester Buildings, customers come to us with a wide range of questions about engineered pole barns. Some know precisely what they want to find out. But, if you’re just beginning your journey to bring your dream building to life and don’t know what to ask, you’re in luck. With the help of Lester Buildings VP of Engineering Services Ted Helmink and VP of Sales Craig Loger, we compiled the answers to these frequently asked questions:

What is an engineered pole barn?

An engineered pole barn is designed to meet all building requirements and load specifications designated for the particular area where the building will be located. From the roof trusses and purlins all the way down to the foundation, every component that makes up an engineered pole barn is constructed to meet or exceed those requirements and specifications. (More on these requirements in a bit.)
What’s more, the materials that make up the components in an engineered building are selected specifically for their strength and durability. At Lester, for example, we use a wood species that’s structurally stronger than the regular lumber that you’d find in a lumberyard. We also have established our own specifications for the raw coil (steel) that comprises our roof and side panels, as well as the systems we use for external paint.

Why is it important to have an engineered pole barn?

The stability of your entire building depends on it. When it’s totally engineered, the building is in sync with itself and will provide maximum durability. 
Not all post-frame pole barns are engineered, and those that aren’t, are at risk of failing. In other words, if your trusses are designed to carry a heavy snow load, but your columns are designed to carry only light snow loads, your columns become a weak link. When that heavy snow inevitably falls, your trusses will hold up but your columns could fail, collapsing that part of your structure (or the whole thing). In an engineered building, there are no weak links.

Lester Building withstands Derecho
In August 2020, a derecho hit the midwest causing devastation across the state of Iowa. Pictured above is a competitor building (1) with an attached Lester addition (2) that only suffers damage on the competitor portion of the building while the Lester section remains untouched. Located in Fairfax, IA. 

What are loads and how do builders decide on design loads for each building component?

A load is the potential amount of snow or wind that a building could be subjected at any one time. There are seismic transfer loads for earthquake-prone areas, as well as snow loads and dead loads (the weight of the building material). As you can imagine, loads and their respective design requirements vary widely from region to region, sometimes even within the same zip code. 
The International Building Code (IBC) specifies load requirements for every county in the United States. At Lester, we’ve entered all of the IBC data into our Improv™ design and engineering software so that, at the touch of a few buttons, our builders and their customers can find out what the requirements are for their building project.

What is the difference between a completely engineered pole barn and one that has engineered components?

As mentioned above, a completely engineered building has no weak links. The entire structure works together as one system. Engineered components, on the other hand, are exactly that – individual parts that may not have been designed to work together as a whole or even within a specific area of a building. For example, a building with a 30-pound load rating on the truss doesn’t necessarily mean that the foundation, columns and roof purlins are designed to carry the same load.

Is there a difference between a pre-engineered and engineered building?

Yes, there is a big difference!  A pre-engineered building is, essentially, “out of the box.” For example, some post-frame builders will assemble packages with a 3 ply 2x6 column and will use that column for everything they build, from a small 24’ x 40’ garage that’s 8’ tall to an 80’ x 200’ building that’s 18’ tall – and everything in between. You can be sure that there is no single piece of lumber on the market today that can successfully handle the loads presented by such a wide range of building sizes!
Other pre-engineered buildings are constructed with prescriptive designs where the builder enters the height and width of a structure into a numeric table that then determines standardized designs for trusses, purlins or other components – with no customization to account for unique situations.
An engineered building, on the other hand, is customized for specific loads, as noted before, as well as for the size of the structure, how it is situated on a property, as well as a customer’s personal preferences such as larger-than-standard overhead doors or windows.

What is a building system?

A system is the integration of all the parts that make up a structure and how they work together to maximize the strength of the entire building. To illustrate: roof purlins bring a snow load onto the truss. The truss takes that load into the columns and then the columns transfer that load into the foundation. If the entire building system isn’t designed to meet required loads, any one of those individual components could fail at any one time.

What is a single source responsible supplier?

Some builders source their materials from different vendors. The trusses might come from one supplier, while the purlins and columns come from another, and steel may come from yet other sources. A single source supplier, like Lester, manufactures its own columns, trusses, purlins and other building components. We also manufacture the steel that serves as the bracing system, roof and side panels. We manufacture the complete package. The key factor here is that we take responsibility for all the material used in our buildings.
As you can see, the more you find out about engineered pole barns, the more you’ll understand why a Lester building can bring you peace of mind that your pole barn will last a lifetime – something we guarantee!
To find out more, download your free copy of Evaluating Your Building Supplier or contact us to find out how we can bring your dream building to life.