I have a small leak somewhere in my drain (ABS) piping and I'm considering doing a smoke or pressure test to try to find it. I know that I need to plug my vent stack to do this but what about the drain? Is there a trap where the main drain line exits the house that would allow me to do this or do I need to find a clean-out and use an inflatable test plug? Any advice is greatly appreciated. Thanks.
Pressure or smoke test
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Do a smoke test and do it from the vent on the roof you won't need to plug anything the smoke will come out where it's leaking I've done a lot of these and never had to plug the drain a water test you would need to plug
Your question is somewhat vague.
How do you know you have a leak?
Is there water showing somewhere?
Follow the water back to the leak.
Is the leak a sewer gas smell?
Then smoke it.
plumb_bob_square_pants
Well-Known Member
Peppermint oil. If the leak is in the house you won't get the smoke in your house. But be forwarned.. be very careful with that stuff. It is potent and you only want to put a drop or two in, no more that that. Cap the vent and use your sniffer. Trust me, you will find it with that if it is dry trap or pin leak. Put it uin the vent.
Peppermint Oil? Now there's a trick I have never heard of.
Still have to use your sniffer to find it.
Smoke is like pointing a finger at the source.
Start with checking to make sure your toilets are set tight to floor and caulked.
any floor drains? maybe one under the washing machine that has a dried up p-trap.
plumb_bob_square_pants
Well-Known Member
Trust me with the oil, Your sniffer won't have to work hard. It's worth a try just to experience how it works. I never would have belive it either.
I tried a peppermint oil test today but without success. I should have mentioned that the sewer gas smell is very intermittent which makes it very hard to locate. I smelled it in mid-June very strongly one evening and then again only last night. What makes the leak even harder to locate is that my basement is fully finished with drywalled ceiling so all the pipe and fittings are hidden.
I put a rag with a few drops of oil in the top of my vent stack and then capped it. I sniffed around the usual problem areas of my house but couldn't detect it. I gave it an hour or more then went back and put a whole lot of oil in the rag but that didn't help. The area with the leak is a long way from my main vent stack so I removed the rag and repositioned it in the vent piping nearer to the leak by removing and replacing a trap. Still nothing.
This makes me suspect that the leak point only opens up once in a while, which is going to make it only that much harder to locate. As I mentioned above, my basement is fully finished and I only have a basic idea of what is behind the walls. I used a borescope today to do a little exploring and discovered a sliding expansion joint near the leak area. Does anyone have experience with this type of joint leaking? It seems more likely to me that it would be the problem area than a glued joint.
Thank you all for your advice.
I put a rag with a few drops of oil in the top of my vent stack and then capped it. I sniffed around the usual problem areas of my house but couldn't detect it. I gave it an hour or more then went back and put a whole lot of oil in the rag but that didn't help. The area with the leak is a long way from my main vent stack so I removed the rag and repositioned it in the vent piping nearer to the leak by removing and replacing a trap. Still nothing.
This makes me suspect that the leak point only opens up once in a while, which is going to make it only that much harder to locate. As I mentioned above, my basement is fully finished and I only have a basic idea of what is behind the walls. I used a borescope today to do a little exploring and discovered a sliding expansion joint near the leak area. Does anyone have experience with this type of joint leaking? It seems more likely to me that it would be the problem area than a glued joint.
Thank you all for your advice.
plumb_bob_square_pants
Well-Known Member
You don't want to use a rag with the oil. You just drop it in the vent and cap it. The oil we use is extremely potent. But the smell will be dificult to locate if it is intermittent regardless of the method.
Good to know. I'm not sure why I thought I was supposed to use a rag but I will try again. Is there a specific brand of peppermint oil you use? I used some Living Essentials aromatherapy oil my wife had lying around. The bottle reads '100% pure peppermint oil. Therapy grade"
plumb_bob_square_pants
Well-Known Member
The peppermint oil we use is like commercial. It's like an 8oz bottle and very strong. I will take a look at it tomorrow when I get back into work. I'll let you know what I find out. But if you have a trap that is dried out or some other leak then you should find it.
I'm pleased to say that I located the leak and was appalled by what I saw. Apparently when running the coax cables, the cable installer bored four holes through the floor right above the drain pipe with a 3/4" auger bit. In one hole he just (I think) touched the pipe with the pilot screw but didn't penetrate it. In two places he pierced the pipe with the pilot screw and in one place he just ran the whole bit right through the pipe. Like I said before, if the basement weren't finished it would have been easy to find.
My diagnosis method was a little unorthodox but, as a DIYer, saved me a lot of cash. I located the drain stack in the basement and identified the fixtures serviced by it and figured out the pipe routing. I opened the drywall and cut the stack. I capped the bottom half and put a series of fittings on the top half that transitioned down to a 3/4" ball valve and garden hose fitting. I then ran cold water from a sink upstream of this point and watched. It took a while to fill the pipe but the leak location was obvious when the water level reached it. I drained it down and opened some more drywall to make the repair. I'm going to water test it all again to make sure the morons from the cable company didn't do any more damage and then start planning my drywall repairs.
Thank you all who responded. Your help is greatly appreciated.
My diagnosis method was a little unorthodox but, as a DIYer, saved me a lot of cash. I located the drain stack in the basement and identified the fixtures serviced by it and figured out the pipe routing. I opened the drywall and cut the stack. I capped the bottom half and put a series of fittings on the top half that transitioned down to a 3/4" ball valve and garden hose fitting. I then ran cold water from a sink upstream of this point and watched. It took a while to fill the pipe but the leak location was obvious when the water level reached it. I drained it down and opened some more drywall to make the repair. I'm going to water test it all again to make sure the morons from the cable company didn't do any more damage and then start planning my drywall repairs.
Thank you all who responded. Your help is greatly appreciated.
plumb_bob_square_pants
Well-Known Member
Take pics and send to the cable company. Wow. That looks like the new what they did and left it hoping it wouldn't be noticed.
