What is that Smell??
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As I originally stated when I started this blog, I really wanted to help people with their plumbing problems and what I couldn’t answer, which is probably 95% of what you would ask, my friends at National Builder Supply would help me find the answers. Well ive had the site up for a couple of weeks and you guys are either not finding me or just don’t have any problems? So Ive decided to address some things on my own and see if they strike a chord with any of you.
I am retired and disabled and spend a great amount of time entertaining myself with my laptop computer reading and responding , everyday, on approximately 30 DIY sites and a few that involve Mercedes Benz autos (my passion other than my children and grandchild). With that in mind I want you to know that the most prevalent question that I see DAILY…. Is “ I have a horrible sewer/septic tank smell that comes from the basement, from the kitchen drain, from the laundry room, etc, etc.” Having experienced this very problem myself and first checking my son’s room to make sure that the smell wasn’t coming from him, I called the friendly local plumber. Now on the forums I’ve read there are several answers to the problem. The most prevalent having to do with a full septic tank, a stopped up line to the sewer line or a clogged vent line. But the easiest to fix and yet least expected is a dry “p” trap.
First let me see a show of hands for those of you that know what a “p” trap is and where to find it?? I don’t see many hands! When indoor plumbing was first invented the wise forefathers thought all you had to do was to just run a pipe from the sink, commode, shower, etc straight to the septic tank, cesspool or whatever. They never even thought of the fact that sewage from the home begins to break down from bacteria (a good thing by the way) and those little bacteria give off methane gas. This gas can do a lot of things more offensive than just smelling bad. It can explode if dad sneaks into the bathroom to smoke, it can suffocate the whole household and both did happen with some frequency. This called for some way to stop the gas from coming back into the house. Thankfully and early genius, whose name escapes me, came up with a simple fix…the “p” trap, simply an elbow in the plumbing line that stays filled with water and keeps the gas from coming back into the house. They also keep Mom’s diamond ring from falling straight down and into the sewer when she drops it in the sink ( a function not originally thought of). If you look under your kitchen or bathroom sink you will see this elbow just below the pipe connection to the drain. There are similar devices built into toilets (more the shape of an “S”), built into walls for plumbing lines like a washing machine drain or other drain lines. If this trap becomes empty then the methane gas backs up into the house and thus the smell and danger.
How does the “p” trap lose its water? Evaporation from a lack of use of a drain, i.e. the spare bathroom that no one ever uses, an over active dehumidifierin the central a/c system(very prevalent in humid states), a washer drain line and you have no washing machine or even something as simple as an old trap that has rusted out in the bottom and so no water can collect, instead you get a small leak and then comes the smell. Where’s that coming from? Somebody use that fancy air freshener I bought for the Bathroom PLEASE!!!.
Now I have seen some other answers for the smell. Even one where the pipes to the septic tank clogged up and backed up against the underground outside wall of the basement and the gas seeped through the concrete block, but that one was rare. My own experience came from buying a vacation home in a rural mountain area with little or no plumbing code and inspections. We soon started smelling a foul odor from the basement and being the plumbing genius I am I thought OK we haven’t installed a washer so the “p” trap for the drain doesn’t have any water in it. Simple fix, pour some water into the drain until we start using a washer. Still had the smell. Now here is where the part about the drain being in the wall and the no code plumbing come into play. To get to the drain line you have to tear out the wall. Was the smell bad enough to make me want to tear out sheetrock and have to replace the whole wall, retape and try to match the paint? Darn right it was . When the wall was torn out and the drain was exposed we found that our mountain no-code, no inspection plumber had just run a straight line from the washer drain pipe out of the house and to the septic tank with no trap. So then we not only had the expense of replacing the wall board, etc we had to figure out how to install a “p” into a wall with little or no room. Too long a story and too much money to even go any further, just know that there can be many issues causing the smell some real simple and others complicated enough to buy a lot of air fresheners and list the house for sale quick.
HOPE THIS HAS INFORMED AND ENTERTAINED YOU. I WOULD LOVE TO HEAR YOUR STORYS. GIVE ME A COMMENT AND SHARE IT WITH ME AND OUR OTHER SHY READERS. WAIT UNTIL I GIVE YOU THE NEXT INSTALLMENT OF PLUMBING PROBLEMS IN THIS SAME HOUSE. YOU WILL FIRMLY BELIEVE IN CODE ENFORCEMENT AND ALWAYS USING LICENSED PROFESSIONALS.
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Comments
Great story, as I will be retiring in 10 or more years, to an island in NewZealand . I have been trying to find out about methane from home septic tanks. This
i recently moved in w/ my mother and three children and i have been noticing this strange smell coming from the bathroom, my oldest daughter and my mother have been having headaches for quit sometime now and iv noticed my head has been hurting as well, i think it could possibly be methane gas! what do i need to do to solve this problem, and how serious is it?
Patty, it can be very serious. Methane gas is not only harmful to your health but can be explosive if enough gathers in a small space. Usually if the smell is coming from a toilet your wax ring that seals the base of the toilet to the drain line as been compromised. The best idea would be to call a plumber to have the ring replaced. This should not be an expensive repair. GOOD LUCK
A few months ago I started smelling a foul odor in mybasement and found a partially decomposed mouse but then could stll smell what I think vis methane gas in the basement, first fllor bathroom and kitchen sink. I had a plummer replace the toilet was ring and check the vent pipe (that was clear of obstructions). THe smell is still there. What could be the problem? We had the septic tank pumped approximately 3 years ago
Bernie,is there a possibilty that these areas are adjacent to an outside wall? I have run into some cases where the drain line from the house was leaking up against the basement wall and the smell seeps up. The other thought is, is there a sump pit or floor drain in the basement? These can some times have a trap that is dried out and lets methane in. I hope this helps.
i have a smell in my hallway,that i can smell in the landing going to my basement stairs,haven't had it for two or so year. now it is back and very strong,it seems like it is coming from the wall just in to the living room, right at the outlet. my husband cut the wall out but no smell in the wall just the outlet.but mostly at the land to the basement.
Shirley
do you have a floor drain or sump hole in your basement? If so check the "P" trap in either to make sure there is water in it. Sounds like adried out trap in some drain in the basement
Hi. Interesting reading! I'm trying to figure out why a sewer gas smell would appear at my mom's house, after not smelling it for the 3 previous years she's been there.
She lives on a concrete slab, cluster home about 13 years old. A month or so ago, it started smelling around her washer machine drain and she says sometimes the kitchen sink, but I have not really smelled the sink yet, however the washer/dryer are located in her kitchen, albeit on the opposite side from the sink.
I would think the code just 13 years ago in a metro Atlanta area would require a P or S trap for a washer drain, but I'm not sure. Today, I ran a piece of wire down the drain to see if I could feel a trap. It showed some resistence the first try about a foot down, so I figured it has a trap of some sort, but trying it again a few times to be sure, it seemed to pretty much go straight down near the floor and stop. Could the trap be that far down?
She uses the washer at least once a week, so don't think it has dried out. I do wonder where and how to check for a sewer vent? I assume on the roof, but what does it look like and how many are there on a typical house? Would a person have to run something down any or all vent pipes and how far?
My mom is elderly and had a stroke 6 months ago, which seems to have made her sense of smell even more keen so I really need to help her. I just don't know if I should start cutting on the drywall to look for the trap or not? I hate to calla plumber just yet and not sure I trust them, sad to say.
I did have the county water co. come out today and check to see if her sewer line was clear. They told her to flush, etc, while they saw the water run into the main line and they said it was clear.
She told me that she has seen dampness around her concrete driveway where there is a crack that follows the sewer line to the street. I guess it's possible that the pvc pipe has cracked someplace, causing that, but not sure it would cause an odor inside, if it were the case. I have not seen that dampness myself, but the crack has been there for a long time.
Any ideas of where to start, I'm all ears, as Ross Perot once said! :)
My guess is that it is a vent problem. vents becpme clogged with leaves and debris and some times animal nests. a simple fix before I would think of breaking sheetrock or concrete is to have the vents augered. the vents are a straight non-capped pipe that stick up out of the roof and she probably has one or 2 depending on the size of her condo and how many fixtures. If you are not adept at climbing on roofs and using a long auger call a plumber. A simple clog can be cleared also with a high pressure garden hose. Even if it wernt a vent problem you would use a smoke test to check for a broken pipe so dont even think of breaking into solid surfaces until you know if there is a leak somewhere.
hope this helps
Let me start by answering the simple questions first. All cities with building codes require a “P” trap system so it’s not likely that your Mother’s problem is a lack of “P” traps but the traps may be involved. More on that in a minute. Secondly you would generally think that water seeping up through a concrete driveway would be water under pressure, so that could be a broken yard irrigation line or a break in the main water line coming from the water source. I would certainly suggest that you check your Mom’s water bill and see if it has recently increased. This type of leak would become more visible with the ground super saturated as with the recent heavy rains in your area.
So now my guess is that it is a vent problem. Vents become clogged with leaves and debris and sometimes animal nests. Here’s where the traps come into play. With a clogged trapped, every time you flush a large amount od water down the drain, such as a washer the drain is starving for air and actually can suck the water out of your “P” traps to be able to breathe. To explain the general principle of why you need a vent, think about playing with a straw in a glass of water. If you hold your finger over the top of the straw water in the straw will not flow out. Plumbing drain lines are the same. They are a closed system that must have a source for air to allow the water to drain out of the house. If the vent is clogged small amounts of water like a bathroom sink or maybe even a toilet will gurgle or bubble while trying get enough air but a washer has enough power to just suck it’s way to the air that its needs. A simple fix before I would think of breaking sheetrock or concrete is to have the vents augered. The vents are a straight non-capped pipe that stick up out of the roof and she probably has one or 2 depending on the size of her condo and how many fixtures. If you are not adept at climbing on roofs and using a long auger call a plumber. A simple clog can be cleared also with a high pressure garden hose. Even if it weren’t a vent problem you would use a smoke test to check for a broken pipe so don’t even think of breaking into solid surfaces until you know if there is a leak somewhere.
Thanks for the ideas! I was there tonight, but only had time to look at the roof for vent pipes from the ground. I see one that is a larger diameter, maybe 4" and then one toward the back of the house, higher up that is smaller, maybe 2 1/2" dia. Do you mean that I can try running a water hose down these pipes a ways and turn on the pressure to try and free a blockage? The roof is not that tall or steep (ranch house), so I think I could get up there. Would these definitely both be vents for the sewer? I'd hate to run water down somthing else! Since you explained the principle of whey they work, I understand that, but where do they extend from? The main sewer line? Is that where the water would run into that I might flush down them?
I agree on the outside concrete crack that is wet. I will check her water bills, however she saw this dampness way before the heavy rains.
Last resort, I will have a plumber try to auger these pipes out. I was just trying to save an expensive service call if it's something I can figure out and do!
Thanks again for your help!
Ted all of the plumbing drain lines are connected to the main waste line to the sewer system and to a central vent stack. water drains because of gravity and a slope created when the lines are installed. Vents are vertical drains mostly horizonal. Unless you were to use some tremendous water force anything flushed down the vent will quite naturally just flow out the waste drains. As to which line out of the roof is the vent it could be either but my best guess is the smaller line but look at the location of the pipes and the vent will be more or less over where most of the plumbing is.
As to the water in the drive way if your seeing it even in dry conditions it must be a heavy leak.
good luck up on that roof, be careful
OK, thanks again! The smaller vent is near the rear of the roof, but fairly close to the peak. I hope that's it! The larger one is toward the front of the house and off to one side. I really have no idea which is closer to the plumbing, but I would assume the smaller one, since the main sewer drain is probably more centered under the house.
I'd sure hate to put water down something else! I will also look in the attic to see if I can get any ID that way.
Take care...Ted
Ted
try this web site http://www.hometips.com/articles/sunset_books/comp
as you can see from their chart a 4" vent would be for a lot of fixtures
I'm hoping there is a simple fix for this...my husband and I just bought an old (built in 1930) riverfront house, and there is a horrible sewer odor coming from the sump pit in the basement. A little background on this basement...prior owners had extensive drainage system work done by Perma-Seal, including a battery backup Super-Sump with a sealed-off "Ultra Sump III" sump pit and drain tile all around the border of the basement. However, there is another sump pit down there that the washer and laundry sink drain into, and it is not sealed off. We bought a cover for it, bought some "Bad Air Sponges" and started running a dehumidifier. This has helped the problem somewhat, but the open pit still stinks. My question is, could there be a "P trap" in this sump pit? If so, where would it be and how do I tell if it's dry? There is always water standing in the pit. We tried running the water in the laundry sink, and the pump does turn on and start pumping so that's not the problem.
We were at the house several times prior to buying it, and we never noticed this smell at all. We also had a home inspection done, and no issues were brought up regarding the sump pit.
Should I try dumping bleach or chlorine tablets into the pit?
Any help you can offer would be greatly appreciated!!
HEY MELINDA
These pits do not normally have a "P" trap and often it is simply the stagnant water that youre smelling. For a quick test to see if the pit ios the problem pour a quantity(enough to thoroughly cover the water) of vegetable oil into the pit which will float on the water and create a temporary seal. At least of the smell then stops you will know thats your problem. If it is you may have to examine some permanent solution to eliminating the pit or installing a pump to keep it dry. Let me know how the oil does.
Thanks for the tip! I will try it out when I get home, and let you know if it works.
As far as a permanent solution, there is already a pump in this pit, and I've heard it turn on and pump the water. Does it mean the pump is not working properly if there is still stagnant water standing in the pit?
I guess I should also ask before trying the oil...since there is already a pump in the pit, will the vegetable oil harm the pump at all?? Want to make sure before I dump a bunch of oil in there :)
Thanks again!!
there should be no problem. these pumps pump a lot worse things than vegetable oil....lol.
even if the pump is working you are still having water standing in that pit and the sewer gas is seeping back in or the water isnt completely being pumped. you will probably need a good plumber to check it out but lets first see if that is the source of the smell. if the oil works we will know thats where the problem is.
Hehe, thanks, I kinda figured that was the case, but wanted to make absolutely sure first :)
I am going to pick up some vegetable oil on my way home from work, and give it a shot.
Know I. Tall says:
9 months ago
Hey Pal - thanks for listing the info. (very helpful). Now I think I can solve a mystery for a neighbor. I'll let you know ...