LW78
New Member
I need some plumbing advice. Our laundry tub pump died the other day and so my husband and I figured now would be a good time to install something like a Liberty 404 or a SaniSwift. Our current system isn’t vented but the new system would be. There are two vents that go out through the roof – one for the kitchen and one for the bathroom – and they’re at opposite ends of the house (small bungalow on septic). The laundry tub system (in the basement) would share the same vent as the kitchen. The problem is that after reading about venting for days on end (I can do basic plumbing like replacing fixtures, but I’ve never dealt with venting), I’m now wondering if our kitchen sink is vented incorrectly.
When we bought our house 20+ years ago, we had some work done before moving in. We assumed our contractor would bring in a licensed plumber, but we were young and naïve so I don’t think we ever double checked. He has since gone out of business due to a reputation for cutting corners and shoddy workmanship, so I wouldn’t be surprised if he did the plumbing himself to save a few bucks. Anyway, the one major change in the kitchen was moving the sink from one side of the kitchen (the original position beside the vent) to the other side. Instead of installing an island fixture vent, whoever did the work put everything under the floor, including the p-trap. So the trap arm runs under the floor from one side of the kitchen, a vent branch runs under the floor from the other side, and then the vent connects to the *side* of the trap arm with a wye.
If I’m right about the kitchen being vented incorrectly, my thought is to reconfigure things a bit (including moving the water supply lines if necessary) so that the trap arm connects to the main waste pipe from the side instead of passing over the water supply lines and connecting from the top. That should create enough room for the vent to connect to the trap arm from the top instead of the side, which should get that connection higher than the trap weir. Assuming that my plan is good up to here, I’m still left with my original issue, which is how to vent the laundry system. Can I simply connect the laundry system vent to that same branch going to the trap arm?
Any and all help/advice would be greatly appreciated.
When we bought our house 20+ years ago, we had some work done before moving in. We assumed our contractor would bring in a licensed plumber, but we were young and naïve so I don’t think we ever double checked. He has since gone out of business due to a reputation for cutting corners and shoddy workmanship, so I wouldn’t be surprised if he did the plumbing himself to save a few bucks. Anyway, the one major change in the kitchen was moving the sink from one side of the kitchen (the original position beside the vent) to the other side. Instead of installing an island fixture vent, whoever did the work put everything under the floor, including the p-trap. So the trap arm runs under the floor from one side of the kitchen, a vent branch runs under the floor from the other side, and then the vent connects to the *side* of the trap arm with a wye.
If I’m right about the kitchen being vented incorrectly, my thought is to reconfigure things a bit (including moving the water supply lines if necessary) so that the trap arm connects to the main waste pipe from the side instead of passing over the water supply lines and connecting from the top. That should create enough room for the vent to connect to the trap arm from the top instead of the side, which should get that connection higher than the trap weir. Assuming that my plan is good up to here, I’m still left with my original issue, which is how to vent the laundry system. Can I simply connect the laundry system vent to that same branch going to the trap arm?
Any and all help/advice would be greatly appreciated.
