Published on September 24th, 2016 | by Henri0
Rodent chews hole in plumbing pipe
Q. A leaking pipe from a 2nd floor toilet proved to be the work of a mouse or rat gnawing inside an elbow. The angle was too acute for metal work so our plumber fashioned an epoxy replacement. Within a few weeks gnawing could be heard at night, so they’re getting in somewhere, but our guys are stumped. We replaced our connection to the city sewer three years ago and are not eager to exhume that work. Is there a way to find and seal the rat door without ripping up the wall and bathroom floor? If not, what do you advise?
A. I assume that you are having a leak in the waste line and not in a water pipe. A leak in a water pipe would be continuous and cause serious damage. A leak in a waste pipe would only show when water is draining from a fixture.
It sounds as if the affected pipe is metal, and it must be a copper pipe, as a galvanized pipe is very unlikely to be gnawed through. But how did the critter get to it is an intriguing mystery.
Mice need a very small hole to get into a house, but rats would need a much bigger hole.
If your guys have not found any hole through which mice or rats can get into the house, and the problem is with a toilet waste line, the culprit may have gotten in by falling into the plumbing roof vent. If this is the case, the critter could have traveled in this waste pipe, looking for a way out, as it’s unlikely that it could get back up the pipe, particularly if it is plastic. When it reached the epoxy connection, it found something that it could chew on to get out.
Is the chewing noise you hear now still in the same location, or do you hear chewing elsewhere in the house? This would indicate that the critter is out of the pipe. If it were still in the pipe, it would seem to me that the animal would have been flushed down the waste pipe when the toilet was flushed.
In any event, you have a leaky pipe that needs to be fixed, so either a wall or a floor needs to be opened up. At the same time, you may want to look into the possibility of changing the sharp bend in the plumbing so the angle in question is no longer so acute.
The damage may represent a weakness in your plumbing, although the damage to it may never recur; this may be a fluke event.by