Wayne Whitney wrote:
Hello,

I'm planning to do a 25' run of 2" cast iron pipe between floor joists
and am thinking about how to properly support it. There are pipe
hangers that I could use to support it from above, so I would have to
attach these to the subfloor. I was wondering if instead there is a
type of support I could use that would attach to the joists on either
side. Something like the expandable bar support on a fan-rated
ceiling electrical box. Any suggestions or pointers?

Thanks, Wayne


Surely not cast iron. Galv steel pipe?

One has to ask, why not PVC?

Have you considered the slope of the pipe?
Over a 25' run, the pitch will eat up 6" of the joist depth.
Add the pipe O.D. to that......

More details. Exactly what are you attempting?

Jim