[Red Squirrel]

There has been lot of talk of flooding in my city latetly due to antiquated sewer systems. I don't think I'm in the affected area but I rather play it safe. I want to install a backflow prevention valve. What is a way I can find out where the main line enters? I could probably get a company to snake it and use a sensor but wondering if there is a DIY way. Would some kind of detector work? I'm guessing it's copper pipe all the way.

 

[rjniles]

Squirrel,

I doubt the sewer line is copper, you are talking about a 4" line.

Do you have access in the basement? If so, it would be easy install the back flow valve in the basement. Might have to demo some concrete if it goes out below the floor.

 

[the_man]

highly unlikely it will be copper. an older home is probably cast iron under the slab/in the crawlspace, and will change to clay or concrete outside the building. talk to your local building department, some have original permits and schematics from installation. other than that, a drain cleaning company can locate the pipe with an inspection camera and also give you a depth reading :thumbsup:

 

[DexterII]

We have copper drains throughout the house, but it transitions to cast iron where it leaves the house and goes to the septic. Anyway, Red, I think that I remember seeing a picture of your crawl space on another post, and it having a concrete floor, so if your waste line(s) go that deep under the house, it won't be real easy. The only thing that comes to mind is to check on the outside of the house to see if you have a cleanout there. After that, you could take some measurements, and should be able to get within a foot of it.

 

[LateralConcepts]

Yep, camera and locator is the easy way.

Maybe you already mentioned this, do you have a full basement with plumbing downstairs? If so, it's probably around 7'-8' deep where it leaves the house.

If you don't have a basement, it's probably only a few feet deep. In that case, you may be able to probe and find it.

It definitely won't be copper. When was the house built? As the others mentioned, it'll stub out of the house a foot or two in cast iron then transition to clay, orangeburg, asbestos, concrete, etc.

Some municipalities keep really good records and schematics. Others don't keep records at all. If they do have an as-built (schematic); depending on which contractor originally drew them, it could be right on the money, or it may look like a child drew it with a crayon.

When you do find it, I'd suggest putting the backwater valve in outside the house to avoid concrete work. I'd also suggest a backwater valve like this: http://www.rectorseal.com/index.php?site_id=1&product_id=316. They're easily serviceable, and easy to take out if ever need to snake the line.

 

[Red Squirrel]

The house was built in 1965 and yeah it is a cement basement/crawlspace (house is split level).

I have a cleanout in the basement floor a bit further down from the main stack, but it's at the back of the house. Could it be possible for the line to actually enter from behind? Seems kinda odd, but also seems odd they would put a cleanout at the end of the run, so I suppose it's possible it meets up with the house behind me then goes to that street.

Come to think of it, could it be that it does a 90 and enters with the fresh water? Is it typical for those to enter from same area or does it vary? Attached a diagram of outlets which may help speculate. Of course I'd still have to get it checked to be 100%. The weeping tile drain is a guess based on the pipes that enter in the sump pit. They might curve at some point, but don't think that really matters.

 

[LateralConcepts]

Yes, there is a possibility it was laid in the same trench as the water service.

It's difficult to speculate based on your drawing. I'm assuming then (based on your initial post) you are on city sewer right?

Is there an alley or easement behind your house? Are there manholes in the street in front of your house?

Is there a cleanout in the main stack also? If so, is it a TEE in the vertical section or a WYE partially buried in concrete?

Is the "cleanout" on the far left of your picture flush in the floor?

 

[Red Squirrel]

Yes, there is a possibility it was laid in the same trench as the water service.

It's difficult to speculate based on your drawing. I'm assuming then (based on your initial post) you are on city sewer right?

Is there an alley or easement behind your house? Are there manholes in the street in front of your house?

Is there a cleanout in the main stack also? If so, is it a TEE in the vertical section or a WYE partially buried in concrete?

Is the "cleanout" on the far left of your picture flush in the floor?

Yes city sewer. There is an easement in the back yard, so I suppose it's a possibility that the plumbing actually passes there. There are overhead electrical wires as well though, so I think the posts would interfeer with any plumbing, but who knows, when it comes to older parts of town. No way they'd be getting a backhoe or any heavy equipment behind here though. There is also sewer drains on my street. There are two storm drains (one on my side of the street and one at other side, and this pattern continues along the rest of the street), and there is a circle in the pavement which I'm guessing is a sewer cover that was paved over... street is VERY rough.

The cleanout is a few inches high and is not flush. there is also a cleanout in the main stack. Was fun getting to that because it was about half an inch in the concrete. I looked inside once but I could not see the end, so it goes at least a foot deep before it does anything.

There is also a drain in the sump pit. I had a main sewer clog once and a bit of poop came out of there, so I do know it's connected. :laughing: I also forgot, near where the fresh water enters, perpendicular (more or less) to the toilet hole, there is also a vent pipe that goes right in the floor. So quite a lot of piping in that one area.

 

[LateralConcepts]

So if you shine a flashlight in either one of the cleanouts can you see which direction they flow? And do they both flow the same direction?

The cleanout in the stack, you didn't answer. Is it a TEE in the stack or a WYE in the floor? If it's a WYE, which direction does it face?

 

[Red Squirrel]

I can't see far enough down to see when it turns because of the odd angle. I'd need a cam. Now that I look at it, the stack is actually 3 inch, it's smaller then normal. The other cleanout near the back of the house is interesting. I've never thought of opening it before, I just did now, the pipe curves and goes towards the outside wall. Nothing else connects to it from that point, that I can see. It's a very smooth curve too, not like a hard 90, or 2 45's.

I'd have to undo the foam cover to see where the toilet flange goes, but I may do that later whenever I get around to buying a replacement piece to fix it back up. Is it a special foam for that, or can I like just cut out some white foam from my latest purchase packaging? I'm suspecting that it goes towards where the cleanout goes and that there is a Y outside the house. Does this make sense? Would a cleanout be setup this way? Think I may be on the right path here. I'd just have to have a look at that toilet one to confirm where it goes.

 

[LateralConcepts]

I'm not sure what you mean by the foam. Maybe just take some pics of the cleanouts that you're talkin' about..

 

[Red Squirrel]

basically, to avoid sewer gasses there is foam that is cut out and put in the hole, then red silicone is added around it. For the cleanout there is a cover so I just made a hole in the foam to see inside and put the cover back on, but for the toilet hole there is no cover, just foam. I guess I can use anything, as long as the hole is blocked after. I'll check it tomorrow to see if the pipe leads out as well.