During this recession, we have repeatedly heard that because of the limited amount of work available, steel fabricators, whether structural or ornamental, are bidding on work they normally would not do. For one ornamental fabricator that meant fabricating a circular staircase for the first time.
Most fabricators turn to companies who specialize in curving steel to purchase the helical stringers required to hold the treads of a circular staircase. And this was the case with this “first timer”. He also used a stringer calculator to aid in his communication of his requirements to the bending firm and to help with the construction.
To make the stair stringers, 12 x 2 x .25 and 16 x 4 x .25 tubes were rolled the “easy way” helically to an 85ft 8 1/8in radius and a 90ft 5 1/8in radius with a 32.26 degree and a 30.85 degree pitch respectively. The stair was designed to turn left as an individual walked up it.
The fabricator decided to construct and erect the full staircase in his shop to guarantee success when it was reassembled at the job site. All the parts fit together perfectly giving the fabricator the confidence not only to make more spiral stairs but also to venture into other complex fabrication areas.