[Shop-talk] reinforcing roof joists

[BJNoSHOV8]

Finite element software?  In college I was taught how to do those 
calculations by hand.

>
> He "boxed in" the 6 or 8 trusses over the stall with plywood, and at 
> the top of each, cut a 2" radius semi-circle.  Then put up a 4" OD 
> steel pipe spanning all of them.  But he staggered the depth, so with 
> no load the pipe was sitting on the outer most plates.  At the 
> calculated flex of the pipe under full load (1100 lbs??) it would 
> deflect and be roughly in contact with all the plates, hopefully 
> distributing the load fairly evenly across all the trusses.
>
> It was "seat of the pants" engineering, and I don't think anyone had 
> FEA software then, but it seemed sound.