Home Improvement → [Plumbing] What is this pipe on side of house for?

I recently bought my first house, and there is a pipe opening on the side of the house. This pipe goes from the outside of the house and pitched down to the foundation, and eventually goes under the concrete slab into the foundation. Inspector said it was related to an old plumping vent, and home depot rep says it was probably a vent for a whole house trap. I am wondering what this is as I am wondering if i can completely cover it, as I have a fear animals/bugs might enter. There are plumbing vents on the roof (I can see at least 2 of them). Anyone know what the purpose of this pipe is/was, and if its safe to completely cover? If not, whats the best way to cover it? FYI, this house was built in 1955, and uses the public sewer system.

I'm not sure, but I'm betting at one time it connected the downspouts from your gutters to the sewer. That was pretty normal in the past, but now most municipalities are requiring that they be disconnected to prevent overloading of the sewer system. There's no reason you can't completely cover it.

Now hold it.

I wouldn't completely cover it without knowing it's function.

Try a peppermint or "smoke" test to figure it out. Where you start with the peppermint or smoke, I don't know, but it's a start.

You mentioned an inspector. If the inspector wasn't a licensed plumbing inspector employed by the authority having jurisdiction (AHJ), I would inquire with the AHJ, and if they give you a one-sentence answer, ask for some history or clarification. Unless your house was a one-shot, the builder and original plumber did this many times, so the AHJ has seen it before. If your AHJ keeps a house file, you should also study it carefully.

Finally, I don't understand your explanation of how the pipe is routed once it penetrates the pictured wall. Do you have a basement? Can you see any part of the pipe inside the basement or crawl space?

Ask your neighbors.

I am not sure if he was a licensed plumbing inspector, he was a whole house inspector, and from what I understand, they just know a tiny bit about everything, not a specialty in plumbing, but I will investigate. I took a picture to better illustrate the portion in the house. This is a split level, and I have a basement, this room is sitting on a concrete slab right by the basement. (I think it used to be a garage), and the pipe goes right into the concrete slab (sorry, i may have the vocabulary wrong, I am still learning). Here is the photo of the pipe going into the concrete.

Also, what would be a good resource or how to on a smoke test?

it's a fresh air vent, sometimes called a cleanout vent, there's a round perforated cover that goes over that, this pipe connects to the sewer trap, cover that, and if you get a clog, you'll have sewer water backing up into your house instead of coming out that pipe!. have someone flush the toilet while you listen at the pipe. this is also used to clean the sewer trap. »www.balkanplumbing.com/f ··· ean-out/

Thanks, that sounds like it makes sense. Will have to try the toilet flushing test . Looks like I will be buying a venting cover. The hole seems to be 6'', do you think »www.homedepot.com/p/7-in ··· 02246288 will work? Trying to figure out how that things hooks on.

No just buy some heavy chicken wire.

You'll need the rest somewhere else

That's basically correct, but the previous characterization as a whole-house trap vent is more descriptive.

On the bottom left side of the added photo, you can see the house trap cleanout plugs sticking up out of the concrete.

The previously-linked site has a very good description and similar photos of the concept, although his characterization of a house trap as "vitally important" is subject to debate, as codes do not uniformly require them.

The diagram I posted is what you have installed, though a running trap with cleanouts isnt used much in my area. The pipe in question is the fresh air inlet for your building drain system, it needs to have free flowing air, cannot be capped.

The pipe coming out of the side of your house is 4" cast iron, you can get a perforated plug to put in there, plastic will be there forever..

Heres a cheap fix.. Get this test plug, drill out 75% of the inner surface with a bunch of 1/4" holes, and caulk it in there. Could paint it also

»www.plumbingsupply.com/c ··· ugs.html (2nd from end of page, 4" test plug)

or.. a shower drain cover from this link.. need at least 4.5-5", depending on your measurements

»www.plumbingsupply.com/d ··· ers.html

edit-- Also.. Check your water main piping for steel pipe with a magnet. Any steel needs to go. Sure looks like a galv nipple and fitting coming out of that valve

-j

Actually it looks like his entire service line (not just a nipple) is galvanized. I would not touch it until ready to replace the entire line.

/M

Buy a vented cover plate. Probably $5 at a plumbing supply house.

What is really weird is that if you look closely at my photo of the inside, you will notice 3 plugs, its kind of hard to see because one is behind the water supply valve. Doesn't a house trap typically have 2 cleanout plugs (just what I gathered from reading the documentation)?

I have all of the sudden become interested in how the sewer line works in this house, and have a fear its going to have to be replaced soon. Looks like there was settling in the house (I just moved in in January), just hoping its not from a leaky sewage line.

Speculation:

The plug behind the water line leads to a wye intended as a cleanout for the line from the house trap to the street.

Or, the plug closest to the vent is a wye as a cleanout for the section from the house trap upstream.

Or, remove the plugs and see what you've got.

Water line is soft copper coming out of floor, I can see the flare nut. Its 1/2" sweat copper after the meter. The nipple and elbow right out of the valve are steel, and need to go.. The nipple right out of the valve even looks like black steel.

I wouldnt mess with any of the cleanout plugs unless you have an actual problem.. If you are worried you may have an issue, find a local guy to run a camera thru the pipe, should be bout 150bux max.. Get a copy of it on dvd

-j