This occupation is included in the larger group of pipelayingfitters, pipefitters, and plumbers.. The median wage for this groupis $4,781 per month ($27.58 per hour). Half of all of these workersearn between $3,602 and $5,651 per month ($20.78 and $32.60per hour).
When supporting joists that span 12 feet with no overhang beyond the beam, a double ply beam can span in feet a value equal to its depth in inches. A double 2x12 beam can span 12 feet; a (2) 2x10 can span 10 feet and so on.
For example, my local code (IRC) specifies that the maximum allowable span for a 2x8 joist depends on the spacing of the joists (which you did not mention in your post), and the species of wood (which you did not mention in your post).