Tag Archives: column cantilevers

Swaying Roof Only Pole Barn

Swaying Roof Only Pole Barn

Yes indeed folks, as probably every owner of a roof only post frame (pole barn) building can and will attest, they sway with the wind.

Reader MIKE in ORLANDO was concerned about his new (not from Hansen Pole Buildings) roof only pole barn moving just from his installing steel roofing panels.

Mike from Orlando writes:

“I just completed the roof panel installation on my open-sided (roof only) Pole Barn structure. It is 38 x 48 with 14 ft eaves. The posts are 8″x 8″x18 ft (4 ft in the ground with full concrete embedment).

While working on the roof I noticed a sway in the structure. As I move around on the roof, the entire roof moves back and forth. It is the poles that are swaying!

This is my first Pole structure (I am self building it from a kit and following the engineered plans).

Is this normal movement? It makes me nervous to walk on the roof – but more importantly, will this be an issue with normal wind forces? Should I add any bracing (like girts between the posts) at the top of the posts to make the structure more rigid?

Thanks for your help.”

Mike the Pole Barn Guru writes:

Your building’s entire roof moves because its columns are working as pure cantilevers – like a diving board. Jump onto an unsupported end of a diving board and even though the board has a well anchored opposite end, the free end flexes. And flexes lots.

Wind (or you installing roofing) causes your building’s posts to act in a similar fashion. Only practical way to reduce or eliminate this will be to cover one or both endwalls from roof to ground with a properly engineered wall (or walls). Unless you truly need to have a just a roof only building, I would recommend you contact your engineer who produced your building’s original plans and contract with him or her to design one or both endwalls for you.

For more reading about roof only pole barns: https://www.hansenpolebuildings.com/2015/04/roof-only-pole-buildings/.




What To Do With an Old Dollar General Pole Barn

What to Do With an Old Dollar General® Pole Barn

In the fall of 2016 the town of Reading, MI purchased the pole barn which had previously been the home of a Dollar General® store. The original plan was to convert the pole barn into a new city hall, but, after seeing the estimated price tag the idea was set aside.

The city’s maintenance man, Bob Jepsen, suggested tearing down the walls, replacing the building’s leaky roof and converting the building into a pavilion. It turns out the city’s planning commission thought this would be a great idea and held a public meeting to discuss.
In the early days of railway transportation, the brakemen rode in the last car of the train – the caboose (seen many of these lately?). He had one of the deadliest jobs in America, as the brakeman had to work from the tops of the railway cars in all sorts of weather.

In the case of the old Dollar General® pole barn, I am going to act as brakeman on the runaway train which is the remodel of the building into a pavilion.
Tearing the walls off of an existing post frame (pole barn) building sounds relatively easy – and from a labor standpoint it may be. Where it all gets dicey is when it comes to structural engineering.

When a post frame building has its walls removed, the columns (posts) now act as cantilevers. They are functioning similar to a diving board, where the end is very flexible. With the walls on the building, the columns are, in most cases, acting as beams supported at one end by the ground and the other by a relatively rigid roof diaphragm.

The difference in the loads which the columns must resist are increased by a factor of four without the walls present, as the posts become the sole structural members for transfer of wind loads from the roof to the ground. This potentially not only impacts the design of the columns, but also of their embedment into the ground.

Whether it is this particular Dollar General® pole barn, or any other post frame building where exterior walls are being considered for removal, a RDP (Registered Design Professional – engineer or architect) should be engaged early on in the process to make a determination as to what upgrades are necessary to result in a structurally sound building.