Drain pipe placement in monolithic pour
I’m building a house on a monolithic slab. The slab turn-down is 18″ wide and 24″ deep. My sink is the only fixture located on an exterior wall. Here is my question: My kitchen sink drain needs to pop through the slab on the exterior wall. To get there, it will need to go either through the slab turn-down, or under it. My trenches are already dug and approximately graded, and as it is now the horizontal portion of the drain is right at the bottom of the turn-down. I could dig it down deeper, which would also require digging the main line deeper, and possibly other branch lines as well. That would put the kitchen sink line beneath the concrete. Is that required? And if so, how far under the concrete is it required to be? Or can I just leave it so that it sits on the bottom of the turn down, but not completely beneath it? Sleeve the horizontal portion in a bigger size of PVC and leave it? Or dig it deeper? The pic shows how it is now, resting right on the bottom of the trench for the turn-down.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
答复
Zoe,
Your kitchen sink drain just needs to be located so it falls anywhere within the cabinet, not necessarily at the exterior wall. That can put it two feet from the edge of the slab.
Thank you for your input! If I moved it out, that would solve this problem, as I could move it out of the turn down. As an added plus, I'd no longer have a drain line in a north facing exterior wall, eliminating the risk of a frozen drain line, and leaving that space for insulation instead. I suppose the downside would be I have less space for storage under my kitchen sink. What do you think?
你将失去一些空间，但是在厨房里的所有机柜中，水槽下面的一个都会产生更糟糕的储存质量。保持漏极尽可能高，然后才能进入机柜墙壁，然后放下陷阱。AAV或芝加哥循环通风口可能值得考虑。
To add to what Malcolm said, I'd try to position things so that the drain is towards the back or either side of the cabinet so that's not in the middle where it will obstruct your storage space. It's not difficult to 90 over a bit from the trap under the sink.
Are you going to vent this with an air admittance valve (AAV)?
Bill
不，我计划常规通风口。把它放在内阁后面让我像以前一样。如果它从成品墙上不超过12英寸，我有板坯拒绝处理。
Zoe, kitchen cabinets typically have a "toe-kick" area where your drain can go--don't exceed 20" out from the finished wall, in order to keep it hidden. Once above the floor, it elbows back towards the wall and then turns up at the back of the cabinet, keeping this section below the bottom of the cabinet, typically a 4" space.
Andy,
An even better idea!
It might be worth putting a sanitary T in a setup under the cabinet, using the top of the T as a cleanout facing up and accessible from inside the cabinet. This way if you ever clog that line with kitchen debris, you have a way to get a snake in around all the bends under the cabinet space without ripping the cabinet apart. Another option might be to make a removable bottom for that particular cabinet to allow plumbing access if ever needed.
It's always a good idea to plan for future service work for stuff like this. A little planning now can save you some real headaches (and a big mess) later.
Bill