Fixing a Smelly Septic Pipe With Fernco Flexible Couplings

I’ve got a fun story for you. You probably won’t want to read it if you aren’t into smelly basements and septic pipes, but if you are, read on. You might be entertained.

When we moved into this house last November, I remember going down to the basement to check things out. One of the many issues I noticed was a slow drip coming from the main septic pipe. The way things are set up in this house is as follows: a main 3″ PVC pipe travels from upstairs all the way down into the basement via an interior wall. Almost all waste water feeds into this pipe through the walls above the basement. The only waste that doesn’t feed into the pipe is the downstairs toilet. That one heads directly into the basement and hooks into the same 3″ pipe, just below the floor. It’s very simple. After the downstairs toilet hooks into the pipe, there’s a 4″ “T” and then a 4″ PVC pipe leads all the way into the septic tank.

Now, I really didn’t give that slow drip much thought. I figured it was something, but perhaps if I didn’t look, it would go away. It would just disappear. Unfortunately, it never did. Thing is, every time I went down into the crawl space to look at the pipes, I really couldn’t see where the drip was coming from. I knew it was there, but all the PVC pipes were coated with spray foam insulation.

Here’s something for you – every time we had more than one person staying with us over the summer, the basement smelled like something died in it. I can remember a few months back, making trips into the basement looking for a mouse in the wall that didn’t make it and that was making the whole joint smell. It didn’t really smell like septic – just like something died in a wall.

Here’s something else for you – a few weeks ago, Laura visited with family for about 17 days. During that time, the basement didn’t smell at all. I hardly used any water at all during that time. Well, a small amount, but not really the big stuff such as the washer, etc…

While Laura was gone, I started thinking. I wondered why the smell in the basement had virtually vanished and why it was so prevalent when we had company over the summer. Just for giggles, I went down in the basement with some tools and began chipping away at the spray foam insulation. Do you want to know what I found?

That’s right, a nasty looking leaky PVC pipe that wasn’t even glued to the 3″ pipe I told you about above. The main one that went through the floor. After I removed all the hard foam, I could easily slide the coupling over the pipe. Back and forth.

Here’s my hypothesis: when we had company over the summer, much more water was being used in the house. Toilets were being flushed, laundry was being done, kitchen sinks were being used. That water usage added material volume to the main septic drain pipe and the plumbing system as a whole. Since a pipe and coupling weren’t properly glued, septic gasses and a tiny amount of waste water was escaping into the basement. Enough to smell like something died in a wall.

When Laura left, not much water was being used at all. In return, there was little to no smell in the basement. Make sense?

By the way, the pipe picture above is after I cut it out of the existing setup.

In order to fix the issue, I had to replace a few sections of pipe. The problem was, since these pipes were already rigidly installed in place, I couldn’t use traditional PVC. I would never be able to connect things. I had to turn to some flexible Fernco couplings.

Here’s how I solved the problem – I cut out the problem area. I felt that getting rid of the whole thing and replacing new was the best way to go. There were a lot of connections there and I had no idea what else leaked. I had three pipes to deal with: one coming from the house straight down, one running horizontally and another horizontal pipe exiting through the basement through the wall. You can see this setup in the picture above.

To connect the main 3″ pipe to the downtairs toilet pipe, I used a Fernco Quik Tee. I then used a PVC street elbow to lead out of the Tee and into a Fernco 3″ into 4″ coupling. From there, I connected that flexible coupling to the main 4″ PVC pipe that goes to the septic tank. If you’ll notice in the second picture above, I cemented a very short piece of 3″ PVC to the street elbow so I had something to bite onto for that lower flexible coupling. By the way, a “street elbow” is just an elbow with a male end. We’re used to seeing two female sides – well this one has a female side and a male side.

I’d say it’s a job well done. The guy in the hardware store called it “redneck plumbing” but I really don’t see what else I could have done. The connections are tight and everything is now dry down there. Also, there is no smell at all. Next to amazing.