Just Another Windy Conversation
Hansen Pole Buildings’ Designer Rick asked me this question today: “Mike, I got a guy who wants to compare an over wind rated building to a Quonset hut at 150 mph” (miles per hour).
Of course I jump right onto this one off the get go, “So the Quonset people have an engineer’s seal on a 150 mph building?” (Just call me a skeptic) “And even if they do – how functional is a Quonset hut?”
I’ve pointed out some Quonset challenges in a previous article: https://www.hansenpolebuildings.com/blog/2011/07/quonset-huts/
Rick, “I’ll check it, but for now I am about to call this guy back, the question is how high can I go up on the wind load and be reasonable?”
Hansen Pole Buildings has created a proprietary pole building design and pricing program which does some truly amazing things….but Rick had me stumped with this one!
For this particular client’s building site the Code wind speed design would be for 90 mph. There is a nifty little formula to convert mph to wind pressure (.00256 X wind speed squared). This makes a 150 mph wind speed applying 277% of the load force of 90 mph.
On this particular 40’ x 60’ x 13’ pole building, the difference in investment for the 277% more force….?
Under 20% more!!
On many pole buildings, designing for extra wind resistance is minimal. For anyone considering a new building, I would certainly encourage them, at the least, to investigate an increase of 10 or 20 mph, at the least.
Next Rick decided to try a 200 mph wind speed (even though no Building Department anywhere in the United States has this requirement). We are now talking wind speeds only an EF-5 tornado would surpass!
Not surprising – our program would design the building…..at 200 mph!!
The sidebar to this story…..
The client wants to be able to pull a trailer out of his new building to live in if his house goes down!