jimrotten
October 7th, 2005, 03:58 AM
I have a 45 year old house. The washing machine discharge backs up over the drain pipe. I will be snaking out the sewer branch to the main.
However, this has me concerned --
from my initial investigation it appears that the washing machine drain does not have a trap or a vent.
I can not confirm this till I return to the house in a couple of weeks at which time I will be removing some drywall to expose the pipes -- my initial look was only through the drywall cutouts through which I could partially see some of the piping behind the wall.
Was it at all accepted 45 years ago to install a washing machine drain (2" cast iron) that would not have a trap or vent??
It appears (I will know for sure when I remove drywall) that the 2" drain goes down to the crawl space without a trap and without a tee to a vent. The drain makes a horizontal jog through one wall stud. It is remotely possible that there is a trap at that point, but I don't think so. It is behind drywall that I did not rip out yet (I looked with a mirror and flashlight to try to see behind the drywall -- I don't think there is a trap). If there is a trap, it is about 10" below the drain pipe inlet. Would that be enough drop from the inlet or should it be moved closer to the floor?
After the horizontal jog (of about 10"), the drain pipe goes down to the crawl space. There is no tee to a vent. It drops down and connects to a 4" sewage branch that runs about 20' to a 6" sewage main. The 20' of 4" cast iron is only used by the washing machine drain, nothing else drains into that entire 20' branch.
Would this likely have been done 45 years ago?
If there is no trap, then the drain pipe is somewhat like both the drain and the vent (as long as the washing machine hose is not connected air tight).
But it bothers me not to have a trap. Would 20' of 4" pipe serve to buffer or hold sewer gases at bay?
Any comments or suggestions (assuming what I described is the way it is) how to make it right?
Do I HAVE to add a trap and vent (or am I grandfathered in)?
Does anyone recommend that I change things even if I am not required to?
If I add a vent, does it have to go through the ceiling and roof? Could it just go up in the wall (an exterior wall behind brick) and stop short of the plate (then potentially allowing sewer gas into the exterior wall cavity)?
Thanks for reading.
However, this has me concerned --
from my initial investigation it appears that the washing machine drain does not have a trap or a vent.
I can not confirm this till I return to the house in a couple of weeks at which time I will be removing some drywall to expose the pipes -- my initial look was only through the drywall cutouts through which I could partially see some of the piping behind the wall.
Was it at all accepted 45 years ago to install a washing machine drain (2" cast iron) that would not have a trap or vent??
It appears (I will know for sure when I remove drywall) that the 2" drain goes down to the crawl space without a trap and without a tee to a vent. The drain makes a horizontal jog through one wall stud. It is remotely possible that there is a trap at that point, but I don't think so. It is behind drywall that I did not rip out yet (I looked with a mirror and flashlight to try to see behind the drywall -- I don't think there is a trap). If there is a trap, it is about 10" below the drain pipe inlet. Would that be enough drop from the inlet or should it be moved closer to the floor?
After the horizontal jog (of about 10"), the drain pipe goes down to the crawl space. There is no tee to a vent. It drops down and connects to a 4" sewage branch that runs about 20' to a 6" sewage main. The 20' of 4" cast iron is only used by the washing machine drain, nothing else drains into that entire 20' branch.
Would this likely have been done 45 years ago?
If there is no trap, then the drain pipe is somewhat like both the drain and the vent (as long as the washing machine hose is not connected air tight).
But it bothers me not to have a trap. Would 20' of 4" pipe serve to buffer or hold sewer gases at bay?
Any comments or suggestions (assuming what I described is the way it is) how to make it right?
Do I HAVE to add a trap and vent (or am I grandfathered in)?
Does anyone recommend that I change things even if I am not required to?
If I add a vent, does it have to go through the ceiling and roof? Could it just go up in the wall (an exterior wall behind brick) and stop short of the plate (then potentially allowing sewer gas into the exterior wall cavity)?
Thanks for reading.