Jogs in the Pipes (?)

In my early 1950s USA house, plumbed in galvanized steel pipe, every point of use is plumbed with about a 12-inch jog in the line. In other words, where the tee in a main run could have been directly in line with the point of use, requiring only a single elbow for the pipe going up thru the floor into the wall, the tee from the main line instead is offset about 12 inches, requiring an elbow for a lateral run of 12 inches, another elbow for another lateral run in line with the point of use, and *then* the elbow for the pipe going up thru the floor into the wall.

I'm wondering why this more expensive method was used, unless it was to add forgiveness for thermal expansion of the pipes.

Thoughts?

Croy,

That does sound odd. If it's on hot and cold, I think you can discard the thermal expansion theory. Here are two guesses. One would be that he routinely did this, figuring it's easier to get the tee on the main in the neighborhood, and then fit up to and through the floor. Some plumbers back then carried nipple packs that went up to 12".

The second guess takes me back to installing threaded black pipe for gas. When roughing in, I'd take as many measurements back to the shop so I could use the big threading machine. It's so easy to be off using this method, that I'd just be happy to hit the right joist space, saving the critical measurements for the job site. While I might use a few more elbows, the time saved by pre-cutting at the shop more than made up for it.

At any rate, threaded pipe isn't nearly as forgiving as copper, and it took a little more skill to put it in.