I’m putting in a new bathroom, and have to tie in to my existing drain under the basement slab. 95 year old house, with a basement. The slab is about 2″ thick, so making a hole is no big deal.
I had to go on a hunt to find a spot to tie in. Where my kitchen drain goes into the slab, there is an old cast iron 2″ clean out. 2 feet away is a 4″ clay tile protruding from the slab. I’ve given the clay tile the sniff test, and really only smell earth. It seems pretty likely that since the cleanout appears to be 2″, it is two inch all the way over to where the main stack enters the slab. But it would be so easy to tie in there, I decided to bust into it and see if by lucky chance it tied to the drain. No such luck. The drain and the tile do not appear to be connected at this point.
so I go over to where the main stack comes from upstairs and enters the slab. I bust a hole about a foot offset from where I expected the line to be, (so I don’t ram the demo bit right into the line) and what do I hit? Clay tile. Further probing and I find the cast iron line right where it was supposed to be.
A few years ago I tore out an old funky shower, and used the drain for that for a sauna floor drain. When I punched into the floor on that gig, what did I hit but clay tile. In that case, the shower was draining into this clay tile.
So what is going on here? I’ve got to think all that tile was some sort of drainage system, but it must be tied into my sewer. Otherwise, how did that old shower function. I can’t imagine it works for drainage, since every place I have hit it, it has been packed in clay (no foot of sand underlying the slab in those days–that basement slab was poured straight onto native clay. Nor is there any perforations, though the tile appear to be joined about every 3 feet, so there are plenty of spots for water to enter it.
I’m thinking I must have a house trap, though I can’t be sure because I can’t get the cleanout open. (I’ll tackle that one when I have to). It does have a vent right where the sewer exits. Maybe that would explain no sewer odor in the clay tile.
I’m going to tie into the cast iron waste line. So it’s really just curiosity.
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Greetings Marson,
This post, in response to your question, will bump the thread through the 'recent discussion' listing again which will increase it's viewing.
Perhaps it will catch someone's attention that can help you with advice.
Cheers
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What did you finally decide to do?
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I posted this more out of curiousity about old houses than really needing to know--I tied into the existing cast iron waste line.I've decided that the clay tile is surely drain tile, and I'd bet money it is tied into my sewer. When I hooked up the new line, I saw that it's pretty well silted up and not functioning, which might be a good thing because my city has a problem with water infiltration into the sanitary sewer system and these kind of set ups are a big problem. Someone really tried to get it right, because there is a lot of it under the slab. Unfortunately, since it is bedded in fine, red, clay, it's hard to believe it did much good. I wonder how water was supposed to get into the system? The fittings are basic bell fittings--was water just supposed to seep in through the joints between the pieces?Thanks Rez for bumping this.