Pole Barn Warehouse longevity

[Kim Donovan]

I am looking at purchasing a pole barn warehouse. The question is around the age of the building. It was built in the 80s. Online pole barn warehouses seem to imply 40 year life spans. Does anyone have any experience with the longevity of a pole barn and what catastrophic event happens at "40 yrs"? Or do they practically last much long, like everything else?

Details: 11000 sqft on a slab, wooden frame, double walled steel walls and slanted steel roof. Everything looks in great shape. We are looking at an 8% cap rate that is already taking into account a possible new roof in the next 10 yrs. We want this to be a buy and hold property for cashflow. Exiting in 10-20 yrs with little to no appreciation needed.