Curious on others experiences with this code and how exactly it applies to how many we actually need to use. It states that every threaded fitting needs to have a support. We don't put a support on the fitting itself, we put it on the pipe before the fitting. But do we actually need to be putting a support on both sides that thread in to the fitting? It seems we do since I often see two supports at elbows, or in many instances, I see the plastic supports cheated on an angle to catch both sides of the threaded fitting on a 90 degree elbow.
I ask because if we really need to follow this code for each threaded side of a fitting, that would mean almost every rooftop I go on does not have enough supports and is not to code.
Depending on the diameter of pipe you would place a support at those intervals specified in the Code. I think you only need to add one support for every threaded fitting, and not on both sides to satisfy the Code. If the support spacing is correct the unsupported side of the fitting should not be able to move.
But what you say makes sense, and when you look at the B149.1-20 Handbook they show both sides of a fitting supported and then different spacing on the longer pipe.
This would be at the discretion of the inspector. I don't do rooftop work but from what you say, most inspectors don't seem to enforce having supports on both sides of a fitting. Based on the B149 Handbook, this could be a quick money maker. Show that picture to the owner, issue a warning tag and charge $500 to disconnect gas pipe, add support and reactivate appliance.
Quote6.25.1
Piping on a rooftop may be supported with treated wood blocks or material having characteristics at least equivalent to treated wood blocks and protection against outdoor exposure. The support spacing. Piping NPS 1 and greater shall comply with Table 6.2, and support shall be provided for every threaded fitting. Piping less than NPS 1 shall be supported
a) vertically according to Table 6.2; and
b) horizontally every 4 ft (1.2 m).
I had never seen that 6.25 picture and further details before. Interesting how there's more information on how to do it that isn't written in the code. Such as using oversized hangers for expansion. I wish it would include a coupling, or Tee's to really know.
My guess would be, since the pipe is steel and the fittings are cast, the fittings would be a weak spot. Stick a block underneath.?
I've seen CSST run across a roof, it looks horrible.