[JESchneider04]

We are putting a washing machine in the basement. The copper supply lines were pretty straightforward to add to our system, but I have some questions about the waste line design. As we get further into it, we've been wondering if our original design is too simplistic.

There is an existing large basin utility sink that is near the washing machine location, and it has a 1-1/2" drain line. There is one trap right beside the main, and a second trap under the sink. The sink is approximately 7 feet from the main. The washing machine is about 15 feet from the main, and you would go past the sink to get to the washing machine. I drew a simple sketch of the system and attached it.

Unfortunately, it is very cluttered on the main near the floor, so if we tap into the main again, the tie point would be a minimum of 32" off the floor and it would be a really big hassle to support the pipe as it would run behind the HVAC, water softener, sink at a really bad height. So, we would prefer to utilize the existing 1-1/2" tie point that the sink uses, and tie in upstream of the trap right off the main. Since it is just a utility sink, it isn't the end of the world if both can't drain at the same time, or if the sink serves as a slight surge basin for the washer.

Final trick to this line: there is a tee in the 1-1/2" line about 6" off the floor (shown in red on my drawing) that is just open to our basement. It is upstream of the trap, so it doesn't let sewer gas into the basement or anything that we've ever smelled. The condensate line from the HVAC and the drain from the water softener sit in that open line so that they can gravity drain. Right now, in the event that either of those connections pops out of the riser, or you try to drain a sink full of water, those connections are right beside some wooden shelves in a really crummy spot to have water on the floor. Being that the open pipe isn't even as high as the *bottom* of the sink, this is just trouble that I'm not sure why someone ever set up to happen.

My questions are:

1. While I know it may not be ideal, will it be legal and acceptable to tie the washer into the existing 1-1/2" drain line connection to the main? We would tie in on the upstream side of the 1-1/2" trap that is right off the main line.

2: Do we need a new vent for the washer (and utility sink too I guess), or does the trap right by the main adequately protect the system because it is in such close proximity to the 4" main?

2.5: I assume the main is vented, but haven't gone to verify this in the attic or anything. Is that a safe assumption?

3: If we put in a riser so that the condensate line from the HVAC and drain from the water softener are higher than the sink but still gravity draining (they would be approximately level with the washer standpipe), is that going to be a problem? I would actually prefer to make more like hard connections with an airbreak directed to a place where I could manage any overflow OK (aka the sump area). I would do this by putting in a riser with a cross on the top, then hardpiping the condensate and water softener drain to the horizontals on the cross, then running an piece of PVC off the top of the cross down to the sump area about 10 feet away. I would leave the piece of PVC to the sump open on the end to provide an air break in the riser to prevent stuff from sucking into the HVAC or water softener. Our sump pit is sealed, but it is still the low point in the basement and a much easier place to clean up any water problems.

4: If the answer to #1 is no, then would it be OK to tap into the main 32" off the floor, put a 2-1/2" trap right by the main, run a 2-1/2" pipe 15 feet over to the washer (the pipe would barely be able to slope toward the drain at all), dip straight down a foot or so at the end to a U, then come straight up into a 2" standpipe for the washer? The top of the standpipe would be about 41" off the ground.

[speedball1]

Before we get into the washing machine let me ask a few questions. Your drawing shows no vents for either the stand pipe or the utility sink. I see so many code violations in that drawing that I'm compelled to list them out
1- no vent on stand pipe.
2-no vent on the sink
3- a open tee off the main allowing sewer gas to enter your home.
4-The main is not only double trapped it's triple trapped.
If that's just one section of your drainage it sure makes me wonder about the rest. Is this a accurate drawing? Regards, Tom

[JESchneider04]

1, 2 - No, there are no vents on the standpipe or sink individually.

3 - No, there is NOT an open tee allowing sewer gas into our home! The main is the line running vertically in my drawing as labeled. There is a 4x4x1-1/2" tee off the main with a 1-1/2" trap IMMEDIATELY adjacent to the main. The tee is on the upstream (the side away from the sewer main with water flowing past the tee, into the trap, then into the main), so the trap right off the main effectively keeps sewer gas out of our home. And no, the main IS NOT triple trapped. The main has NO traps in it - it is the vertical line that runs down into the floor and out to the sewer.

4 - I wouldn't have posted this drawing if it was inaccurate, so yes, it is an accurate drawing. And, no, there are not "so many code violations in that drawing". I've spoken to the county building codes department at length about the design. The venting of the standpipe & sink are the only potential violations, and I think I'll just call them back on Monday to work through that issue.

[speedball1]

, 2 - No, there are no vents on the standpipe or sink individually.

Two code violations right there. Standard Plumbing Code, Chapter 7, Section 703.1

3 - No, there is NOT an open tee allowing sewer gas into our home! The main is the line running vertically in my drawing as labeled. There is a 4x4x1-1/2" tee off the main with a 1-1/2" trap IMMEDIATELY adjacent to the main. The tee is on the upstream (the side away from the sewer main with water flowing past the tee, into the trap, then into the main), so the trap right off the main effectively keeps sewer gas out of our home. And no, the main IS NOT triple trapped. The main has NO traps in it - it is the vertical line that runs down into the floor and out to the sewer.

Sorry I miscalled the branch a main but that still doesn't give you permission to double trap a drainage line,( Chapter 7, Section 703.6) and then to install a open tee in the drainage branch and expect a running trap to keep the sewer gas generated in the branch out of your home. Or don't you consider the branch line to be a part of your drainage system and thus exempt from existing codes? Both the standpipe and the sink are in violation of chapter 7, Section 703.6(b) which reads" Full "S" traps are forbidden".

4 - I wouldn't have posted this drawing if it was inaccurate, so yes, it is an accurate drawing. And, no, there are not "so many code violations in that drawing".

Then, if, after you claim your drawing is correct I stand by my statements about the violations and have listed as my source The Standard Plumbing Code.

I've spoken to the county building codes department at length about the design. The venting of the standpipe & sink are the only potential violations, and I think I'll just call them back on Monday to work through that issue.

Yeah I guess the venting would be a issue for the inspector. And yet he OKed the open tee? Work through the issue of no vents plus the "S" traps in addition to the double trapping? How do you plan on working through a faulty design without going back and correcting the code violations?
You have asked us for a opinion and you have mine. Repair the violations, correct your drawing after the changes and get back to us. Cheers, Tom