Basement Floor Drain Backs Up When Toilet is Flushed? (Fix It Now)

Ryan Womeldorf
by Ryan Womeldorf

It can happen when you least expect it. You come into your basement only to find that the drain has overflowed, leaving raw sewage piping into your basement. The first thing you need to figure out is why. If the answer is the basement floor drain backs up when the toilet is flushed, you’re in the right place to deal with the problem.

If your basement floor drain backs up when the toilet is flushed, a clog in the sewer line is the culprit. This is usually caused from non-flushable items going down the toilet, tree roots growing in the sewer line, or even using too much toilet paper. Some issues you can resolve on your own, but you should always contact a professional to deal with invasive tree roots.

If you’re currently dealing with this issue, read through this article to get to the root of the problem. We’ll go over the do’s and don’t’s of dealing with this issue as well as the main causes. Furthermore, we’ll talk about how to prevent backups from getting worse and happening again in the future.

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Why Does the Drain Back Up When the Toilet is Flushed?

The reason that your floor drain overflows is that the sewer line has a blockage somewhere down the line. This is different than a clog where you can simply plunge the toilet and go back to living your life.

These backups in the drain are usually further down the line. They can simply be due to non-flushable items being flushed—and there are plenty of them—or it could just be a build up of toilet paper. In the absolute worst case, you could be facing the issue of tree roots that have invaded the sewer line.

Non-Flushable Materials

According to a survey commissioned by the SCOTT® Clog Clinic, more than one in five people in the United States deal with a blocked toilet at least once every year. Many times, the reason for your drain backing up is that you have sent non-flushable items down into the sewer system. Avoid flushing products like…

  • Feminine products. You should never flush pads or tampons down the toilet as they can easily clog the system. Instead, wrap them up and throw them away.
  • Facial tissues. Though they look like toilet paper, facial tissues are not designed to break down in water. This will cause clogs, leaks, and overflows over time.
  • Paper towels. Like facial tissues, paper towels will also not disintegrate in the toilet right away. The result will be clogged pipes and costly repairs.
  • Flushable wipes. For the most part, even if it says that you can flush these types of wipes, they do not break down in the same manner as toilet paper and instead will clog the pipes.
  • Coffee grounds will build up and restrict water flow rather quickly. What may start as a minor annoyance will quickly turn into sewage backups and expensive repairs.

It is surprising just how many people treat their toilets like garbage cans. The sewage system in your city–in any city–is only meant to handle toilet paper and raw sewage. When you flush anything else, you run the risk of a clog.

Those clogs will then result in sewage coming back up through your floor drain. You may be able to handle minor clogs on your own, but your safest bet is to get in touch with a plumber right away once you start experiencing problems.

Tree Roots

Believe it or not, some blockages will not be your fault. For instance, raw sewage is actually filled with nutrients that trees love. Because of those nutrients, tree roots will actively seek out the natural moisture of the sewer line. If you think that you have tree roots invading your sewer line, a professional needs to come out as soon as possible to resolve the issue.

Most sewer lines aren’t simply punctured by those roots, thankfully. That said, roots can be persistent and will eventually find an entry point into the sewer line. When they finally get inside, they will continue to grow until they catch hold of sewage and toilet paper.

From that point, the roots will work with the sewage and toilet paper to clog up the line. All of that means trouble for you, which means you should work to resolve the issue as quickly as possible.

Toilet Paper

It’s true that toilet paper is one of the only items that ever should go down your toilet, but that doesn’t mean it still doesn’t cause problems. In fact, it is one of the biggest culprits of toilet drain backups. How can this be? For starters, many people tend to use way more toilet paper than they need. Not only is this a waste, but it’s also the quickest way to clog the sewer pipes.

The best way to avoid this problem is to use as little toilet paper as you need. In situations where you need to use a lot, flush more than once instead of putting it all in the bowl at once. Moreover, there are actually better types of toilet paper you should use to avoid clogging your types. Here are the takeaways:

  • 100% recycled toilet paper is the absolute best option. It is the most dissolvable, making it the safest for your plumbing system. However, it is more expensive.
  • One-ply toilet paper is a great choice when it comes to solubility once put in the toilet. The downside is it may not be as comfortable to use.
  • Two-ply toilet paper is not the worst choice for your toilet, but certain brands are better. Specifically, Angel Soft 2-Ply is still a decent option.

How Can You Prevent Further Backup?

The main water line is how all of the water that comes from the city’s water supply gets into your home while the sewage line is the way out. The sewer line works to connect all of the drains in your house to the central sewer system.

When there is a blockage, things can get messy rather quickly. If someone flushes the toilet or even tries to take a shower with a blockage present, the basement floor drain becomes the lowest unblocked point where the water can exit. Here’s what you can do to stop the backup from getting worse.

Turn Off the Water Supply

To prevent further blockages, you have to find the shut-off valve and turn off the water supply. It can be in your home, typically on the street side of the home. If you can’t find it, call the water company immediately. There will be a shutoff at street level that they can activate to cut off the water flow into your home.

Locate the Sewer Cleanout Pipe

One of the first things that plumbers will do when they arrive is to access the sewer cleanout pipe. If you want to find it before they get there, you can save yourself and your hired plumber a lot of time. Plus, you may be able to avoid an extra charge some contractors tack on if they have to locate it themselves.

This pipe is usually found somewhere in the backyard. However, in colder climates, the sewer cleanout pipe may be somewhere in the home or garage. Just walk around the house and look for a pipe that juts straight up. It is typically black or white PVC.

You might not be able to find the pipe right away because it’s not used frequently. Check in bushes or other plants to find it. If it is in your home, then it is probably in a utility closet, basement, or garage. Remove the cap if you can; doing so will relieve a bit of the pressure that has built up in the sewer line.

Call in a Professional

Unless you’re dealing with a small clog, there is no DIY fix when it comes to a backed up sewer line. In most cases, you should not attempt to fix the problem on your own. There is a chance that you can do damage to the city’s sewer line, which will end up costing you a lot in the long-run.

Plumbers have both the knowledge and tools to get the job done properly. Some of these tools include sewer cleanout tubs, cameras and snakes, hydrojets, and special chemicals to kill root systems.

If the blockage is minor, they can typically snake the problem. But if a hydrojet is required, things get more complicated (and expensive). A hydrojet is a high-pressure water jet that can cut through those non-flushable items but it requires care to avoid damaging the pipes.

How to Clean Up Your Basement After a Backup

Even after you find and fix the problem, the work isn’t over. So, what should you do with all that water that flooded your floor? The simple answer is: clean it. The extent of that cleaning, however, will depend on the size of the flood.

If it was smaller and didn’t reach any of the running electricity, you are fine to clean up yourself. In the event of a more serious flood, you may have to bring in a professional to assist with the cleaning. Here are the steps you should take if you can clean up on your own.

Step 1: Air Flow

If there are windows in your basement, open them. Get some fans going, too. Not only will this make the smell more bearable, but it will also help with the cleaning too. You’ll be able to get rid of those noxious gases and allow the air to naturally dry up the liquid.

Step 2: Remove the Sewage

Should there be any physical remains of the sewage, now is the time to get rid of it. You can use a broom and dustpan to avoid having to get down to grab any left over debris. However, this can be annoying if the floor is still wet after airing it out. If that’s the case, you may want to use a mop or towels to gather the debris into the corner.

Step 3: Cleaning Solution

Drying the floor isn’t enough; you need to clean it thoroughly. So, at this point, you’ll need a cleaning solution. With a bit of low-sud soap and some hot water, it’s time to scrub. Make sure that you get any area that the sewage touched, rinsing away the mixture with hot water after.

Step 4: Sanitize

After cleaning the area, you have to sanitize. Use a mixture of bleach and water to properly sanitize everything. Make sure that you have good air flow and ventilation as bleach is definitely something you don’t want to breathe in.

What Not to Do When Your Drain Backs Up

Whenever there is an issue at home, there are generally two reactions: do something about it or call a professional. And while taking action can sometimes be helpful and even save you a few bucks, there are instances where this can actually be a bad idea.

In the event of tree roots, there is nothing that you can do on your own. Only a professional has the tools and experience needed to handle this project. You simply run the risk of prolonging the problem, making matters worse.

You also should not try to unblock the drain or dump any chemicals into your drain. When done improperly, either of those things could wind up damaging the city’s sewer system. When that happens, guess who is responsible for fixing the issue?

The bottom line is you really shouldn’t try to tackle the issue on your own if your basement floor drain backs up when the toilet is flushed. Namely, this is because it shows there is probably a larger problem at hand than a simple clog. More likely than not, something is happening deep down in the sewer line.

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Our Final Thoughts on What to Do When the Basement Floor Drain Backs Up When the Toilet is Flushed

When it comes to dealing with a basement floor drain backup, the best thing you can do is call a professional. Truthfully, this is your only option when it comes to dealing with tree roots. To avoid these backups in the future, be sure to only flush toilet paper and waste, use the right type and amount of toilet paper, and perform regular maintenance to stay ahead of issues before they arise.

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Ryan Womeldorf
Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

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