Potential for Clogs and Backups?

**Nick Ostrowski** · 03-13-2009, 08:08 AM

I saw this yesterday. The PVC line is 4" pipe and the cast iron line it connects to does not have a stated diameter but appears smaller but it is hard to tell for sure because it is partially embedded in the wall. The brass cleanout cap on the cast iron setcion has 3 1/2" stamped on it.

Is the 3 1/2" figure just the diameter of the cleanout opening or is this indicative of the actual diameter of the cast iron line too? I'm also wondering if the actual thicknesses of the different pipes may create or prevent a possible clog issue at the connection. There are stains on the wall beneath the connection but no moisture showed in the area by the end of the inspection so it is possible the stains relate back to the original reason the PVC was installed.

Any thoughts?

Similar Threads:

**Wayne Carlisle** · 03-13-2009, 08:20 AM

Is the pvc just a vent or does it go to a fixture above it (2nd floor)?

If it's just a vent...no problem...if it is to another drain...may be a problem...that would make it a wet vent. But it still may not be a problem. Depends on what's upstairs if there is an upstairs.

**Nick Ostrowski** · 03-13-2009, 08:23 AM

It's an active drain line for a 3rd floor bathroom.

**brian schmitt** · 03-13-2009, 08:36 AM

nick,
looks acceptable to me. the 3 1/2" cleanout is standard for a four inch line. code prohibits reduction of pipe size except for a 4" to 3" water closet bend. jerry?

**John Arnold** · 03-13-2009, 08:36 AM

Just curious, Nick - Do you often recommend that the underground portion of the sewer pipe be scoped when the property is quite old and some or all of the accessible portions of the pipe have been replaced?

**Nick Ostrowski** · 03-13-2009, 08:55 AM

I do not John but considering what happens to cast iron over time and how bad some visible above ground sections look, I can only imagine what the underground lines look like. I may need to add that to my recommendations.

**Jim Luttrall** · 03-13-2009, 09:30 AM

Originally Posted by John Arnold

Just curious, Nick - Do you often recommend that the underground portion of the sewer pipe be scoped when the property is quite old and some or all of the accessible portions of the pipe have been replaced?

I recommend pressure testing lines anytime there is an apparent foundation problem (98% slabs here) or if the house is old enough to have cast iron drains. They say the life expectancy of cast iron is between 50 and 100 years but I have seen lots of it fail at 30-40 years.
Scoping with hydrostatic testing would be even better.