Any plumbing experts?

[70herald]

Well there are experts for just about everything here.. so maybe someone would have some ideas...
Strange problem... every few weeks our spare room is suddenly overwhelmed by an overwhelming sewer gas smell.. either no smell at all or from nothing to full on the hydrogen sulfide devil -the smell of death has emerged from under the floor.
Oddly enough there is no smell in the bathroom right next to the spare room so the gas doesn't seem to be escaping through the p-traps in the shower/sink/toilet. The drain pipes from the bathroom runs directly under the spare room floor and are connected directly to a manhole in my driveway which leads to the city sewer.
Drain pipes around here are push together pvc (well some sort of plastic) with a rubbery o-ring. Pipes were checked when we renovated a few years ago and all is well - in any case we had the same issue before the renovations also..
Is it possible that H2S gas pressure is building up in the sewer? last time this happened about 1/2 hour later, I opened the manhole... and there was no sulfide smell, not flooded.. could their be a "burst" of H2S suddenly building up in the sewer?
If the smell isn't coming from the sewer where else could it come from?

 

[NutmegCT]

Hi Yisroel - H2S gas is explosive. Get a professional's guidance on this.

There are many things that can cause gas to escape the pipes and surprise you. Air pressure (in the pipes as well as ambient), humidity changes, rainwater, etc.

Vent the area best you can to get that gas out of the living area. In Israel do houses have basements? or just crawl spaces? Public sewerage, septic systems, cesspools?

Let us know what a professional says. This needs fixing!

Also, happy Pesach to you.
Tom M.

 

[70herald]

Hi Tom,
My place is concrete slab directly on the ground (well obviously there is a foundation somewhere) no crawlspace, maybe 12 inch max between the slab and the tile floor and that is filled with gravel, concrete, insulation and heating pipes. Not much room for gas to accumulate.

I actually have had several plumbers looking at the system, problem is the stink comes every few months, takes a few minutes to hit instant death.. and then disappears until it randomly comes to visit again. So by the time the plumber arrives there is nothing to see or smell.

This time I tried to get the closest manhole up l open to see if there was something unusual going on, but by thr time I got it opened... Everything was back to normal.. almost makes me think it is something other than the sewer. Just no idea what it could be.

 

[BigGreen]

Get a camera in the pipes to view from their inside
A crack is often visible that way

 

[bobhustead]

When the water in the bowl evaporates or otherwise gets much below normal levels, there will be created an air gap thru the soil pipe trap. Next time, try pouring water into the bowl, which will fill the trap, and close the air gap. I suggest that the sudden disappearance of the smell coincides with flushing the toilet, thus refilling the bowl to proper levels. If this happens frequently, water is getting out of the toilet- to- flange joint or the soil pipe upstream of or in the trap system.
Bob

 

[NutmegCT]

Agree with Bob. Same thing can happen with a tub or shower drain, and/or a main sewer line gas trap; if water level somehow drops past the gas trap bend, unpleasant things happen.

 

[bobhustead]

Been years since I plumbed a new toilet and was rusty on whether a trap separate from that in the toilet itself (built into the soil pipe) is used. Don't think anything other than the trap cast into the bowl is used in residential. Any trap will potentially produce the same problem. Don't know why odor collects in an unplumbed room, but I still smell a trap.
Bob

 

[bobhustead]

I just remembered that a friend had a similar problem in an old farmhouse. turned out that a disused and disconnected but not properly plugged branch of the drain system was right under a window.
Bob

 

[70herald]

Well here is what I have figured out.. (or at least think for now)
Not the traps. I have checked them 10 times in and they are still full with water. Also still the smell is clearly coming from the wrong location. This "experiment" has repeated itself enough times over the last few years that I am very sure of it.

Two nights ago, I opened an access port on the main line going between the front and back sides of the building. My apartment is built into a hill so I have a private entrance on one road and then at the top of the hill on the other side of the building is the main entrance into the apartment building about 20 feet higher. At the higher level.. there are a series of manholes which collect the mess and then send it through a 6" pipe around the outside of the building, to a manhole sort of directly behind the basketball hoop and then another 6" pipe which then runs under my driveway, through several manholes and out to the city. I opened the access port about 5 feet above the level of the manholes in my driveway.. just enough for it to vent. Late at night it "exploded" leaving me with a clean up job (outside)
Normally - even a peak time there would only be a "flow" in the main line - certainly not explosive force at the access point. Even when we have had our local "Rothschild's Sewage and Septic Sucking Services" clean things out there has never been that kind of pressure... they have cleaned the system with that port open. So it looks like upstream one of the manholes is filling up and eventually dumping creating a huge blast. Clearly something needs cleaning.

On my side, I most likely need to add a check valve like this which would be good to protect my apartment anyway from flooding - next week when building supply places open up again after the holiday I will need to go look at them and see if they will help against gasses.

 

[2002S2000]

I can't add much except to say the venting has to be right and can affect many functions of the drain system, I'd guess you're on the right trail! Your home and the Jerusalem stone(?) is beautiful, having been in that area several times I always found the architecture enchanting. Are there many LBC's in the country?

JS

 

[NutmegCT]

"Rothschild's Sewage and Septic Sucking Services"



That is hysterically funny!

Thanks for the details on the drain systems at your apartment building. It really seems that the owner of the building should be fixing the problem - or at the very least, let you see construction and plumbing drawings illustrating all the lines, connections, and valves.

What does the owner say?

Tom M.

 

[70herald]

"Rothschild's Sewage and Septic Sucking Services"



That is hysterically funny!

Thanks for the details on the drain systems at your apartment building. It really seems that the owner of the building should be fixing the problem - or at the very least, let you see construction and plumbing drawings illustrating all the lines, connections, and valves.

What does the owner say?

Tom M.

Asking the owner won't really help in this case since I am the owner. Almost all apartments in Israel are privately owned so I own my apartment, and some percentage of the hallways, roof etc (really a liability since I can't build on the roof just responsible for maintenance costs) Newer / bigger buildings usually have a professional management company but they still are only the manager, not owner. We have an older guy who manages the finances and there is a limit to how much I want to bug him because if I bug him too much I might accidently inherit the job.

I have a copy of the construction drawings - at least what was filed with the city for approval. They are noticeably light on detail and may or may not reflect what was actually built.

 

[waltesefalcon]

"Rothschild's Sewage and Septic Sucking Services"

 

[70herald]

I can't add much except to say the venting has to be right and can affect many functions of the drain system, I'd guess you're on the right trail! Your home and the Jerusalem stone(?) is beautiful, having been in that area several times I always found the architecture enchanting. Are there many LBC's in the country?

JS

Back in the day... there were a number of LBCs or cars built using the same mechanicals. Of course back then the country was also rather poor and there weren't that many cars overall. My Herald would have been considered a rich persons car at the time. More common would have been the cheaper sedans, or commercial vehicles. Sporty LBCs would have been almost non existent. I know of a few well restored British cars, a few Frenchies or Italian cars and you still see Beetles on the road every few days.

My place is covered in Jerusalem stone. We consider ourselves extremely lucky to have this place.