Longtime lurker, and finally came up with a question that couldn’t be answered by reading another post…
I recently moved to a 1940’s cape that has 2” and 4” cast iron drains, and galvanized vents. All the drain/waste/vent plumbing appears to be done properly, except perhaps the existing laundry drain, which I’d like to relocate anyway.
The washing machine and utility sink drain into the into the main drain in the basement just above the cleanout. It’s an “unconventional” setup. The sink drain and laundry standpipe are tee’d together upstream of a drum trap, and the outlet of the drum trap drains into the main soil pipe as it leaves the house and heads towards the street. There’s no vent nearby, but on the other side of the basement, there’s an unused 2” waste pipe that has what appears to be a dry revent pipe connected, and it’s the last connection tee’d into the main stack before the laundry, so I assume this is acting as the vent for my sink and washer? The current setup works fine, but, the sink is raised up about 18” so it can gravity drain, which makes it awkward to use, and it’s in an inconvenient spot, so I’d like to relocate the laundry/sink elsewhere.
My goal is to remove the existing sink/standpipe and cap where it connects to the drain, and then install a new utility sink elsewhere in the basement, with an under-sink pump (like a Zoeller 105) to pump the waste to the drain. The unused 2” waste pipe and vent I mentioned above are located right near where I’d like to put the laundry, sink, and pump, so hopefully it’s an easy install, but I have a few questions:
1. The Zoeller pump has a check valve on the discharge, so in the event of a backup on the main drain, I won’t get an overflow in the basement. I recently had this occur, and my existing laundry sink overflowed, which was much preferable to an upstairs toilet! Anything I'm missing here, or will the lowest "flood rim" in my house now be moved up to the main floor?
2. The sump of the Zoeller needs a vent connection, which I can easily tie into the vent that’s currently tee’d into the unused 2” waste pipe. I’m unclear on if the pump discharge connection to the waste pipe also needs a vent. Since it's pumped, and the pump basin is vented, is that sufficient? The rest of the drains/traps in the appear to be vented properly, and I've not had any issues with gurgling or siphoning.
3. If the discharge pipe does need a vent, my only existing option would be to tie it into the same vent that the basin would be using. But, if I do this, in the event of a backup of the main drain, this horizontal vent could fill with waste, since the discharge pipe has a check valve. The “flood rim” of the utility sink doesn't exist, since the discharge has a check valve on it. I’m not really opposed to this scenario, because I think I’d rather have the vent for my utility sink fill with waste than have an upstairs toilet overflow…But, I don’t want to do anything wrong/stupid.
4. Bonus question: I don’t mind draining the washer into the utility sink, but would prefer to install a dedicated standpipe for the washer to keep the sink area clear, and have both the sink and standpipe drains connect to the pump basin. Is this possible?
Apologies for the long post and crude pictures. I've omitted the other drains that tie into the main drain in the basement, as the all appear to be vented properly, and are upstream of where the laundry tray pump would tie in.
Thanks!!!
I recently moved to a 1940’s cape that has 2” and 4” cast iron drains, and galvanized vents. All the drain/waste/vent plumbing appears to be done properly, except perhaps the existing laundry drain, which I’d like to relocate anyway.
The washing machine and utility sink drain into the into the main drain in the basement just above the cleanout. It’s an “unconventional” setup. The sink drain and laundry standpipe are tee’d together upstream of a drum trap, and the outlet of the drum trap drains into the main soil pipe as it leaves the house and heads towards the street. There’s no vent nearby, but on the other side of the basement, there’s an unused 2” waste pipe that has what appears to be a dry revent pipe connected, and it’s the last connection tee’d into the main stack before the laundry, so I assume this is acting as the vent for my sink and washer? The current setup works fine, but, the sink is raised up about 18” so it can gravity drain, which makes it awkward to use, and it’s in an inconvenient spot, so I’d like to relocate the laundry/sink elsewhere.
My goal is to remove the existing sink/standpipe and cap where it connects to the drain, and then install a new utility sink elsewhere in the basement, with an under-sink pump (like a Zoeller 105) to pump the waste to the drain. The unused 2” waste pipe and vent I mentioned above are located right near where I’d like to put the laundry, sink, and pump, so hopefully it’s an easy install, but I have a few questions:
1. The Zoeller pump has a check valve on the discharge, so in the event of a backup on the main drain, I won’t get an overflow in the basement. I recently had this occur, and my existing laundry sink overflowed, which was much preferable to an upstairs toilet! Anything I'm missing here, or will the lowest "flood rim" in my house now be moved up to the main floor?
2. The sump of the Zoeller needs a vent connection, which I can easily tie into the vent that’s currently tee’d into the unused 2” waste pipe. I’m unclear on if the pump discharge connection to the waste pipe also needs a vent. Since it's pumped, and the pump basin is vented, is that sufficient? The rest of the drains/traps in the appear to be vented properly, and I've not had any issues with gurgling or siphoning.
3. If the discharge pipe does need a vent, my only existing option would be to tie it into the same vent that the basin would be using. But, if I do this, in the event of a backup of the main drain, this horizontal vent could fill with waste, since the discharge pipe has a check valve. The “flood rim” of the utility sink doesn't exist, since the discharge has a check valve on it. I’m not really opposed to this scenario, because I think I’d rather have the vent for my utility sink fill with waste than have an upstairs toilet overflow…But, I don’t want to do anything wrong/stupid.
4. Bonus question: I don’t mind draining the washer into the utility sink, but would prefer to install a dedicated standpipe for the washer to keep the sink area clear, and have both the sink and standpipe drains connect to the pump basin. Is this possible?
Apologies for the long post and crude pictures. I've omitted the other drains that tie into the main drain in the basement, as the all appear to be vented properly, and are upstream of where the laundry tray pump would tie in.
Thanks!!!
