An Introduction To Post-Frame Buildings

By James T. “Tom” Knight, formerly of the National Frame Building Association

I admit to being somewhat taken aback when someone asks me, “what is post-frame.” Why so surprised? Well, people drive by them every day. In fact, they potentially drive by a great many post-frame buildings. Problem is, they just don’t realize it.

Maybe I shouldn’t be surprised. On the outside, post-frame buildings look like any other building you might drive by. They might have a steel exterior or roof, but then again, they might have wood, stone, brick or any other siding, or a shingle roof. There really are no “rules of thumb.”

On the interior however, things are decidedly different. First and foremost, post-frame buildings are wood-framed buildings. In post-frame construction, solid-sawn posts or laminated columns act as the primary support system for the wall and roof systems. You won’t see what may be thought of as “traditional” wood studs, steel framing or a concrete block wall.

Pre-engineered trusses are affixed to each post or supported by a header. Horizontally placed dimensional lumber (called purlins on the roof and girts on the walls), secure posts and trusses and form the basic frame. Exterior sheathing, commonly steel, OSB or plywood, provides lateral load resistance. All together, post-frame components create a unique building diaphragm that makes the light wood frame comparable in strength to steel and concrete structures.

Now the question is: So is this an advantage? It’s actually an advantage on numerous fronts. Post-frame structures are much more quickly erected than other kinds of buildings. Because the posts and the interlocking frame can handle greater loads than stud-wall construction, less structural materials are needed. That saves on material and installation costs. The significant savings in construction time and material yields a quality building in less time, for less money.

The economies of post-frame don’t end there. The natural insulating properties of a wood structure are superior to those of other construction types. Also, because posts are spaced farther apart than studs, there are fewer interruptions in insulating materials. Post-frame buildings feature an exceptionally large wall cavity that is easily insulated. That means lower heating and cooling costs throughout the year.

Post-frame buildings are durable, long-lasting, and adaptable to virtually any architectural style. As an added bonus, they are exceptionally resistant to wind, snow and seismic loads. In areas ravaged by hurricanes and earthquakes, often the only structures left standing are post-frame.

Modern engineering technology has resulted in post-frame today being recognized as a truly significant advancement in the centuries-old art of wood-frame construction. Post-frame is now the construction method of choice for any number of commercial, retail, industrial, residential, religious and public building needs.

Post-frame construction has proven so efficient and versatile that the agricultural building market, where post-frame was first introduced, now constitutes only a fraction of the total post-frame market. Post-frame design is recognized by every building code and standards for all types of building applications. For all kinds of one and two story buildings, from small garages to clear-spans as wide as 106 feet, the inherent advantages of post-frame make it an excellent choice.

So the next time you’re looking at a beautiful building while driving down the street, there is a good chance you are looking at a post-frame structure. It might be a strip mall, convenience store, restaurant, office complex, school, church, bank, fire station…the list is really endless. Post-frame is today the method of choice for an ever increasing number of discriminating building purchasers – and building designers alike!

James T. (Tom) Knight is the former President of the National Frame Building Association. Tom holds degrees in Journalism and Personnel Administration from the University of Kansas and a Juris Doctor degree from Washburn University School of Law in Topeka, Kansas. He is a licensed attorney (on inactive status) in the State of Kansas.

The National Frame Building Association was founded in 1970 and represents the nation’s post-frame construction industry including builders, component manufacturers, steel roofing and siding producers, building material distributors and design professionals. For more information, go to www.nfba.org.

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