In its most basic form, a pole barn is a fairly simple agricultural building or storage structure with widely spaced posts rather than studs for framing. Back in the 1930s, farmers often used old utility poles to build these buildings. Since the poles were usually deeply buried (typically 4 to 6 feet deep), they provided both foundation and vertical structure.
These days, most pole barns are more sophisticated than the dirt-floored pole barns of the 1930s. Pole barns have evolved into so-called “post frame buildings,” and an entire industry has sprouted up to build them. Instead of used utility poles, post frame buildings use pressure-treated 6x6s or 8x8s for posts. While many post frame buildings still rely on buried posts, others have conventional concrete foundations. Even when posts are buried, it’s common to install a slab floor after the roof has been installed.
Between the widely spaced vertical posts, these buildings have horizontal girts, generally 2 feet on center. Typically, 2×4 or 2×6 lumber is used for girts. The girts are covered on the exterior with siding (usually, steel panels). Some, but not all, post frame buildings have OSB sheathing between the girts and the siding.
Common in rural areas, many post frame buildings are used as barns, equipment sheds, and hangars. More elaborate post frame buildings are used for a variety of commercial buildings or even homes.
In this article, I’m going to use the term “pole barn” to describe simple structures with widely spaced poles or posts rather than studs to support the roof. The buildings I’m talking about are uninsulated and usually lack sheathing. In most cases, the siding consists of either vertical boards nailed to horizontal girts, or steel panels nailed to horizontal girts. These buildings have either a dirt floor, a gravel floor, or a concrete slab…