Maximum possible pipe lengths in bar joists

[SprinklerDesigner2]

This came out of an old Automatic Sprinkler or Grinnell designers handbook back in the days when mostly everything was threaded and pipe scheduled.

It was an easy to use formula for estimating the maximum length of pipe able to fit in a bar joist. You had to know joist centers, total depth and thickness of upper and lower joist chord members.

I remember this worked rather well adn for the life of me I can't find it or remember exactly what it was.

Anyone?

 

[drow57]

I have been in the industry since '78, 10 yrs with GFPS. I have a copy of a design manual from '72 and this information is not posted in there. What are you trying to accomplish? We routinely use 20' lengths of 1.5", 2" and 2 1/2" welded pipe in the joist space (24" BJ) on 6'-8" centers.

 

[sfallows]

I quite often use 21' lengths (std length for most pipe manufacturers)

if your not sure just draw up a quick section and example pipe to see how it would fit

 

[TravisMack]

SD2,

If I remember correctly, it is the joist depth (in) / 6 * joist spacing (ft)

So, If you have 24" deep joists at 4'-6" on center, you could have 24/6*4.5 or an 18' stick of pipe would go through the joists.

This at least got me in the ballpark and I never had fitters call me and say they couldn't get the piping through the joists that I sent out.

I know this doesn't take into account the chord depth. It was just something an old sprinkler guy taught me when i got started almost 20 years ago.

Travis

 

[SprinklerDesigner2]

"If I remember correctly, it is the joist depth (in) / 6 * joist spacing (ft)

So, If you have 24" deep joists at 4'-6" on center, you could have 24/6*4.5 or an 18' stick of pipe would go through the joists.

This at least got me in the ballpark and I never had fitters call me and say they couldn't get the piping through the joists that I sent out.

I know this doesn't take into account the chord depth. It was just something an old sprinkler guy taught me when i got started almost 20 years ago."

That's it!

Thanks.