If your smelling sewer gas or a methane gas smell in a room, ceiling, wall, or any room for that matter, you can trouble shoot the leak by using smoke.
You can purchase smoke emitters from any HVAC supply house. They will remind you of a smoke bomb that is used on the fourth of July.
The other method is purchasing a smoke machine or renting one at your local rent-it-store.
Lets look at some plumbing behind a wall. See picture.
Here you see a typical plumbing connection for a clothes washer. At the bottom near the floor is a clean-out fitting. At the top is the vent line that either connects with another vent but the vent eventually goes out the roof. See picture.
If your not sure your vent line goes out the roof like the above picture shows, you will need to follow the plumbing fixture vent line up through the attic and determine if the vent is actually going out the roof.
If the vent line is going out the roof, than you will need to proceed with the smoke test. If the vent line is not going out the roof than you have found your problem in the attic and you will need to vent the sewer vent line out the roof.
Let me tell you what I have seen over the years as to why you may have sewer or methane gas in your house.
True story: I have many stories but I’ll use this simple one. A dental labatory was smelling methane gas on and off for months. This was a new building less than one year old. I was called in when others failed to find the smell. I began tracing the vent lines from six sinks. When I got close to where the lines coonnected on a branch vent, I found that a sanatary tee that was tapped in line for future sinks, actually had the cap off of it. I installed a new cap and the problem was fixed and they never called again about that problem.
The moral of my story is don’t take anything for granted. Just because the building was new doesn’t mean that it was tested properly.
Testing a vent line with smoke bombs or a smoke machine.
This is a two person job what I call the buddy system. One person is on the roof if possible and the other is in the house, or commercial building. You would first put the smoke down the vent stack in the area where you smelled the foul ordor or where others told you where they smelled bad odors. You don’t have to at this point cap any sewer lines off if you can see smoke coming out of the ceiiling, wall, floor, etc. You will be able to isolate the bad piece of pipe right away if you get lucky.
If after the first try of the smoke test you get nothing you may have to isolate a sewer line in the area of the complaint. See caps and plug picture.
If you have to get to this part of the DIY instructions I advise you call a plumber. You will have to cap the end of sewer lines and check each vent individually.
What causes vent lines to go bad or other pipes in walls, ceilings etc. to get hole in them?
The answer is simple from what I have seen.
1.) Poor plumbing installation
2.) lack of plumbing inspection
3.) Poor installation again, by not properly allowing for expansion and contraction of plastic chemical pipes, and all other plastic pipes used in homes and commercial buildings. Thereby causing pipes to pull and stain and cause cracks, which causes methane gas smells.
4.) Old galvanized, lead, durion, cast iron, 30 -50 year old pipes leaking at and in joints, connections.
5.) Remodel jobs even when the plumbing wasn’t touched. When old lath or drywall was removed a screw possibly left in for ten years is know removed causing a smell of methane during new remodel.
6.) Manufactured piping material that was not the same thickness the entire length of pipe, and was not leaking at the time of a pressure test but leaks 5-10 years later due to weakness of the material.
7.) If I left anything out like vandalism, revenge, or any other act of man I’m sorry.
Also check out my other article on methane gas detecting by using peppermint oil.
Amazon.com has my new book available to look at, It’s called “Flush Your Plumbing Troubles Down The Toilet”.
Check it out.