Why Is Water Backing up in the Bathtub After I Flush the Toilet?

Your drain pipe might be the reason why sewage is backing up into your bathtub

Have you noticed a large pool of questionable water in your bathtub after you flushed the toilet? Besides being absolutely disgusted, you probably also suspected something’s not quite right.

What causes this nasty plumbing problem? The most likely culprit is a clogged sewer line.

In this blog post, we’ll explain:

• Why a Clogged Sewer Line Can Lead to Dirty Water in the Tub
• Other Signs You Have a Clogged Sewer Line
• The Main Causes of a Sewer Line Clog
• How to Fix a Clogged Sewer Line

Let’s start by looking at how a clogged sewer line can cause water to back up in the tub.

Need a plumber to clear the sewer line? Call Red Cap Plumbing or request an appointment online. We’ll quickly dispatch one of our Tampa plumbers to find and clear the source of the clog.

Why a Clogged Sewer Line Can Lead to Dirty Water in the Tub

The drains that connect to all of the plumbing fixtures in your home (toilets, sinks, bathtubs, etc.) feed into one main sewer line. The main sewer line carries waste away from your home and into a city wastewater treatment facility.

Normally, when your drains and the main sewer line are clear of debris, water flows quickly and effortlessly out of your home when you flush the toilet (as seen in the image below).

Diagram of a healthy drain system 

However, if there is a clog in the main sewer drain line, wastewater will get directed to the next opening. In this case, the nearest escape path is your bathtub (see image below). 

Diagram of main sewer line clog

Unless the clog is very severe, the water in your bathtub should eventually empty out within a few minutes and go back into the main sewer drain. But it still leaves an undesirable mess in your tub.

Other Signs You Have a Clogged Sewer Line

Besides water backing up into the bathtub, you’ll also know you have a sewer line clog if you notice the following signs:

• You Have Multiple Slow-Draining Sinks and Bathtubs
• The Water in Your Toilet Bubbles After You Take a Shower or Run the Bathroom Sink
• You Can See Sewage in the Sewer Clean-Out
• You Can Smell a Rotten Sewer Odor Coming From Your Drains

What causes sewer lines to clog up in the first place? Let’s take a closer look …

The Main Causes of a Sewer Line Clog

Several things can cause a sewer line to clog, including:

• Tree roots: As roots search for water, they can force their way into an old sewer line and create a clog.
• Grease buildup: Even though grease goes down your drain as a liquid, once it cools and congeals, it will form a solid mass that will clog up your main sewer line.
• Insoluble products: Products such as condoms, tampons, baby wipes, and paper towels can clog the main sewer line if flushed down the toilet. Instead of flushing these products down the toilet, dispose of them in a trash receptacle.
• Broken pipes: Plumbing pipes can break down over time. If the sewer line has formed a leak, dirt, and debris can enter the pipe and form a clog.

One of these issues likely explains why your sewer line is clogged, but how can you fix it?

How to Fix a Clogged Sewer Drain Line

For clogs in the main sewer line, you’ll need to contact a plumber for a professional drain clearing.

Here’s why: Deep underground clogs in the main sewer line are difficult to reach. To reach the clog and clear it, the plumber will need to use advanced equipment.

First, the plumber will perform a video inspection using a drain camera to find the exact location of the clog. Then, depending on the location and severity of the clog, the plumber will use one of the following tools to clear the clog:

• An auger: If the clog is not too deep in the pipes, the plumber may use an auger (a metal plumbing snake) to try and dislodge it.

Tree roots taken from plumbing pipes with an auger

• Electric drain clearing cable: This machine uses a retractable wire coil that can extend over 200 feet in length, which makes it perfect for clearing clogs deep in your home’s main sewer line.
• Hydro-jetter: A hydro-jetter blasts high-pressure water in the pipes to break up clogs and clean the inner lining of the pipe. If the clog is especially tough (such as clogs caused by tree root invasion), the plumber may recommend a hydro-jetter for the job.

Want a Reliable Florida Plumber to Clear Your Sewer Line?

Call Red Cap Plumbing or request an appointment online. We’ll quickly dispatch one of our skilled plumbers to unclog your sewer line.

Learn more about what to expect when you hire us by visiting our drain-clearing page.