HellNY
New Member
Id like to know if anyone can diagnose this problem.
Hard to believe but its true. I am a homeowner (not plumber). We recently had an entire bathroom remodel . We had a sewer gas smell coming from our new shower drain. We entertained all sorts of possibilities including inadequate venting (siphoning off the water in the trap, etc). But the vent is clear. Then I found toilet paper floated up into the shower drain. A small amount. We then did a "blue water" test by filling the toilet with clorox-blue tablets which makes the water blue. After flushing the toilet, eventually we see the blue water inside the shower drain.
This is on the 2nd floor of a single family home. I have discussed this with the plumber.
More details:
1. The celing and floors have been sheetrocked so I cant test pitch directly yet. But the shower drain (its a 2 inch) joins a sink drain and then heads north for about 8 feet, then turns abruptly east for about 18" and joins a 4-way intersection of 3 inch sewer pipe. To visualise this 4-way intersection, imagine you are standing in the center of the intersection: the shower drain comes from the west. The tub drain (separate) comes from the south, and the toilet drain comes from the east. All to one place. They all have a northward "sweep" that sends all sewage/drainwater to the north down into the sewer.
2. Added detail: when the sink drains, which is right next to the shower (its drain joins the shower drain before it heads north to the sewer intersection), the shower trap water level swells a bit and then falls back again when the sink completely drains. This implies that somehow, sink water also gets into the shower trap.
Possible explanations: The plumber swears up and down the lines are all pitched properly. He says one eighth of an inch per foot. I know he used a torpedo level when he worked but I do not know how he knows the exact slope. Yet this seems like a pitch problem to me. Or there is not ENOUGH pitch so water can flow "uphill" before it drains? Second: the toilet sends sewaged into that intersection on the exact opposite side from where the shower water enters. Although this is 4-way PVC drain pipe that is all gently "sweeped" northward, isnt it conceivable that some of the toilet water surges directly across this intersection and then, through its own momentum, carries it enough to travel the 8 feet or so to reach teh shower trap upstream? At an eighth of an inch of pitch per foot, it would have to rise up about 1 inch.
Im not a plumber but something like the above has to be happening.
The plumber suggests installing a check valve in the shower/sink drainline just before it reaches the 4-way intersection. This seems like an expedient way to solve it, but any future snaking woudl get trapped in the valve (never snake again). Should I just open the ceiling so he can do this or should I expose it all and check the entire system. Any and all input welcome.
Hard to believe but its true. I am a homeowner (not plumber). We recently had an entire bathroom remodel . We had a sewer gas smell coming from our new shower drain. We entertained all sorts of possibilities including inadequate venting (siphoning off the water in the trap, etc). But the vent is clear. Then I found toilet paper floated up into the shower drain. A small amount. We then did a "blue water" test by filling the toilet with clorox-blue tablets which makes the water blue. After flushing the toilet, eventually we see the blue water inside the shower drain.
This is on the 2nd floor of a single family home. I have discussed this with the plumber.
More details:
1. The celing and floors have been sheetrocked so I cant test pitch directly yet. But the shower drain (its a 2 inch) joins a sink drain and then heads north for about 8 feet, then turns abruptly east for about 18" and joins a 4-way intersection of 3 inch sewer pipe. To visualise this 4-way intersection, imagine you are standing in the center of the intersection: the shower drain comes from the west. The tub drain (separate) comes from the south, and the toilet drain comes from the east. All to one place. They all have a northward "sweep" that sends all sewage/drainwater to the north down into the sewer.
2. Added detail: when the sink drains, which is right next to the shower (its drain joins the shower drain before it heads north to the sewer intersection), the shower trap water level swells a bit and then falls back again when the sink completely drains. This implies that somehow, sink water also gets into the shower trap.
Possible explanations: The plumber swears up and down the lines are all pitched properly. He says one eighth of an inch per foot. I know he used a torpedo level when he worked but I do not know how he knows the exact slope. Yet this seems like a pitch problem to me. Or there is not ENOUGH pitch so water can flow "uphill" before it drains? Second: the toilet sends sewaged into that intersection on the exact opposite side from where the shower water enters. Although this is 4-way PVC drain pipe that is all gently "sweeped" northward, isnt it conceivable that some of the toilet water surges directly across this intersection and then, through its own momentum, carries it enough to travel the 8 feet or so to reach teh shower trap upstream? At an eighth of an inch of pitch per foot, it would have to rise up about 1 inch.
Im not a plumber but something like the above has to be happening.
The plumber suggests installing a check valve in the shower/sink drainline just before it reaches the 4-way intersection. This seems like an expedient way to solve it, but any future snaking woudl get trapped in the valve (never snake again). Should I just open the ceiling so he can do this or should I expose it all and check the entire system. Any and all input welcome.
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