The Both Ends Open, Pole Barn Wind Load Challenge
There are plenty of people who just do not understand the basic concepts of how wind loads are transferred through a pole barn (post frame building) to the ground. Included amongst these would be those who desire buildings which are enclosed on both long sidewalls and open on both ends. This is one of the worst possible design concepts one can come up with in a new post frame building.
Of course somewhere along the discussion between the Building Designer and the client this statement always seems to come up:
“Well Joe Blow has one down the road and his is still standing”.
My response to this is – “Joe has just been phenomenally lucky”.
In my years living in Eastern Washington, we made numerous trips from Spokane to Seattle. Driving across Interstate 90, one passes through the towns of Moses Lake and Ellensburg. This is prime grass growing country, where numerous hay storage buildings have been constructed over the years, with both ends open. The majority of these now have complex systems of braces and/or extra diagonal columns added to their sidewalls in attempts to maintain them standing vertical. More than a few of them only remain standing up because they are full of hay – the contents alone are what is keeping the buildings standing.
I’ve hashed through this challenge in the past, however it is apparent too few people have read and grasped the situation (read more here: http://www.hansenpolebuildings.com/2017/04/open-endwalls-hay-barn/).
For those of you who enjoy audience participation, please go find an empty shoe box and a pair of scissors.
Remove the lid (and the shoes) from the shoe box. Place it open side down on a table top. Push down on the box – pretty stable, isn’t it?
Next, cut both of the narrow ends completely out of the box. Again place it open side down on the table and push on it…..
Flat as a pancake, isn’t it?
The very same concepts work to keep buildings standing. Remove too much or all of the ends and the building does a fall down, goes boom.
Just because Joe happens to have a building standing which sound engineering practice says it should not be, does not make it right. Most folks are going to make a significant financial investment into a new post frame building and my personal preference is for them to not have their insurance company paying to replace the building.