Currently redoing my own bathroom remodeling and made a discovery I’ve never seen before in all the other jobs I’ve done — a mysteriously spontaneously splitting cast iron drain line.
My cast iron sewer drain has this mysterious crack that developed along the length of the pipe right after it turns horizontaly from vertical. This line services the second floor bathroom, dropping vertically into the basement where it turns horizontally to go through the foundation wall into the public sewer system. I been in my basement numerous times and never recalled once seeing this horizontal split, or crack. It’s along the top of the pipe, running horizontally about 16 inches and about 1/8″ to almost a 1/4″ wide in some places. Nothing leaks out of it, yet you can kinda look though the crack and see well….you know, gunk. I’ve done a lot of work around cast iron and never seen it split before. Nothing fell on it because it’s in an out of the way area.
Any theories/explanations? Guess I’ll be replacing it soon with PVC which will fortunately be easy since its 100% accesible.
Thanks
Replies
I've worked on a few older homes (i.e., 1920ish) where the original cast iron DWV pipes have failed along the seam that runs lenghtwise along the pipe. The places I have seen it are in vertical spaces, in wall cavities, behind lathe and plaster that needs to be carefully cut out and then repaired after the pipe is replaced. You are fortunate yours is accessible.
Hub cast iron was before my time. But when working with it sometimes we would notice some pipe was much thinner all the way around than others. The old-timers told me that during the war (WWII I presume) they saved on materials by making it thinner walled.
Yesterday I couldn't even spell plumber, today I are one.
Recently, I was in a crawl in Albuquerque. The house was around 100 yrs old and was built on a stone foundation that had never been re-pointed. The girders were supported in a very haphazard way by unvertical props. It was very obvious that the house had experienced inches of miscellaneous settling in a variety of ways and planes.
The soil stack on the other hand seemed to have been well supported by its horizontal run out under the footer. So there it stood, vertical and well-supported, attached to the frame of the house by its various branches.
When I saw it, this horizontal section below the main ell had a 1/4' split that ran for 5 or 6 ft. My inference was that the settling of the house applied weight to the stack which in turn then attempted to bow the horizontal waste line. Being brittle, the cast iron split to relieve the applied force. Differential settling rates caused by uneven settling between heavily weighted perimeter and lightly weighted girder piers (or soil stacks) is often responsible for producing strange effects, the cause of which aren't immediately apparent.
Lance
Had to replace about 25' of cast iron horizontal run with PVC for my aunt, two years ago, for the same continuous split down the top of the pipe. Couldn't see the crack from a standing position and so at first I assumed that the sewer odor was due to a faulty floor drain trap. When that didn't pan out, I looked further. My fingers discovered the crack which averaged about 1/4" in width. It's a ranch built in '72 and there's no signs whatsoever of settling. The cause? I dunno.
cheap chit CI pipe is the culprit.
Still gotta watch what you buy.
I bought a duplex once to rehab. After getting it all most complete we started hooking up all the finish plumbing and flushed the toilets for the first time. And the wall instantly got wet floor to ceiling. Same crack you are describing. Mine was caused by a vacant house getting numerous animal nests in the stack. Then when it rained it filled with water and froze and broke. I also agree with Wethead, in the "good old day" there were still cheap products and poor workmanship done daily just like today. You got what you paid for generally. DanT