“Can You Tell Me How to Find the Main Sewer Line in Your House?” Lisa in Sacramento Asks an Expert

Lisa in Sacramento is having some plumbing troubles that necessitate knowing how to find the main sewer line in your house. She writes:

“I don’t want to overreact here, but there is something seriously wrong with the plumbing in my house. I live in Sacramento, on the grid but not that close to the capital, so my house is a little bit older. Anyway, we have an upstairs and downstairs bathroom, and dirty water keeps coming out of the drain in my bathtub downstairs. It’s gotten to the point that my family and I will now only take our showers upstairs.

Before writing to you, I did do a little bit of asking around. One of my neighbors said the exact same thing recently happened to her. What a coincidence (or is it?). She told me that the problem was deep in her plumbing, and it turned out that the most important thing to know was how to find the main sewer line in your house because that’s where the trouble was. So that’s what I want to know today: can you tell me how to find the main sewer line in your house? And, what’s your advice for fixing my problem after I find it? Thanks!” – Lisa in Sacramento, CA

First and foremost, Lisa, you were right to bring your residential plumbing question to the expert team at Bell Brothers. Next, let me just say, yikes, that is one nasty problem! But don’t worry, we can indeed tell you how to find the main sewer line in your house, what to do once you find it, and how to fix what I suspect is a broken pipe or a very nasty clog.

The Easiest Way to Find the Main Sewer Line in Your House

If you’re dealing with sewage backing up into your tub like Lisa is, you’re almost always also dealing with a main drain clog or a break. The first thing to do in this situation is to figure out how to find the main sewer line in your house.

The most effective way is to start by locating where your drain line exits, which is usually in a crawlspace or a sub-basement.

The most effective way is to start by locating where your drain line exits, which is usually in a crawlspace or a sub-basement. Finding this can help you narrow down your search for the main sewer line. Just find one pipe you know for sure is a drain that connects to a toilet or sink, and then follow it until it connects with a larger diameter pipe. Then trace that pipe until it exits the basement or crawlspace.

That drain pipe almost always goes into your sewer line, which will at the very least show you which side of your house your sewer line is buried on. Basically, once you locate your larger drain pipe, you play a game of detective, following it until it exits your property into the main sewer line itself.

How to Find the Main Sewer Line in Your House Using Alternative Methods

If you don’t have a crawl space or a sub-basement—or if you do but you just can’t seem to find one of those larger drain pipes that we talked about—don’t worry! The thing about old houses in Sacramento like Lisa’s is that a lot of them were built in really unique ways, which means that they’re all different.

Luckily, there are a few alternative ways for how to find the main sewer line in your house, including:

• Ask the previous owner: This is exactly as simple as it sounds. Are you in touch with the previous owner of your home? Well then, give him or her a call. They may have the answer to this conundrum.
• Check with the city: Another outside actor who may know exactly how to find the main sewer line in your house is your local government. A trip to your local zoning or building office (or maybe just a phone call) might clear things up right away. Knowing your property lines well will also help you rule out some of the areas since your sewer line won’t be on a neighbor’s property.
• Locate your septic tank: This is not likely to help someone like Lisa who lives on the grid in Sacramento, but for folks in further-flung locales, I highly recommend this option. If you have a septic tank, the sewer lines in your house will lead out from your sub-basement or crawl space directly to that tank. So, find the tank and then work backward from there.

What to Do Once You Find Your Main Sewer Line

Here’s the thing, though. Once you’ve found your main sewer line, it’s not an instant solution to pipe and plumbing troubles. In fact, that main sewer line almost always goes underground—where it becomes very hard to reach. You can check and dig once you find it, but if you’ve never had experience with this sort of plumbing work before, it’s somewhat likely that you might actually make things worse.

My advice once you find the main sewer line—or before—is to call a plumbing professional to figure out whether you have a drain clog or a pipe break, and next steps for how to fix it.

My advice once you find the main sewer line—or before—is to call a plumbing professional to figure out whether you have a drain clog or a pipe break, and next steps for how to fix it. A good plumber will have all the know-how and experience you need. Finally, if you’re not convinced that you have either a clog or break, look at your utility bills. If you find yourself wondering why your Sacramento sewer bill is so high, it’s a good indication that you have an issue and should just go ahead and call a plumber immediately.

I hope this is helpful, not just for Lisa in Sacramento, but for anyone else who ends up searching for their main sewer line. There are a lot of things that can go wrong with your sewer system in your houses, so knowing what to look for and why is really very helpful.

In the end, though, if you have sewage backing up into your bathtub like Lisa described, odds are that you’ll have to go on ahead and call out a plumber. Working with a main sewer line often means digging into walls or underground. It’s easy work for a trained professional, but much harder for you! Let the pros get their hands dirty for you.

Get in touch with the plumbing professionals at Bell Brothers to learn more about your home’s plumbing and sewer health. Our trained professionals will offer recommendations for maintenance and upgrades that are sure to increase your water efficiency—and decrease your water bills at the same time.

Wondering how to finance a new HVAC system, windows, or plumbing project? HERO is a unique financing option that helps California homeowners afford energy efficient upgrades to their home. Contact Bell Brothers, a HERO-approved contractor, to learn more. Our local HVAC, plumbing, and window specialists will walk you through the entire process, from applications to installation.

Image courtesy fizkes