Today’s inspection is a residential home, 4/4, 2,635 sq ft, built in 1949, on a crawlspace. During the exterior inpsection I noticed an odd PVC vent pipe on the rear exterior of the building down near grade level. In the crawlspace I saw a PVC pipe connected to a waste drain. The PVC pipe ran to the rear of the crawlspace and exited at the location of the exterior PVC vent pipe. This is an unusual setup for me. I’ve looked (googled, code check) and haven’t seen a horizontal vent of this type. Also, why would the put it in the middle of the pipe in the crawlspace? Is this some type of configuration that is used on older houses where you can’t go up throught the roof?
The first picture shows the exterior pipe, the second and third pictures shows the pipe in the crawlspace, the third picture shows the pipe connecting to the waste pipe.
It is not fun, but a good way to tell if it is a plumbing vent is to stick your nose on it and take a big sniff. It’s not 100%, because sometimes there isn’t much smell coming out, but if there is a smell, you will know it!
Evening, Anthony.
Hope to find you well.
No issues except for the trap.
I can’t find code reference but I will be on the other computer later.
When I have seen, ran into this, exterior plumbing vent configuration in older homes, which I have on multiple occasions, was due to the main vent stack, a cast iron hub and spigot, where blocked.
Typically, the second floor bathroom sinks and bathtub would guggul when emptying and drained slower than the kitchen sink on the first floor.
Hope that helps.
Hey Robert, Thanks for the info. That seems to make sense. I suspect the trap would be dry as there’s now water flow through the pipe and it’s too far above the main pipe (roughly 2-3 ft). But, I could be incorrect.
If it is a drain vent, I have to disagree about the “no issues” statement. It needs to be routed up higher, preferably above the roof line. That thing will occasionally be belching some fairly significant sewer gasses.
It’s probably an attempted plumbing vent. You can vent out the side and up, but not like that (especially with a trap).
Just state that appeared to be a plumbing vent that was improperly installed and have a plumber blah, blah, blah…
No gases and no venting, lol.