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How to Fix Basement Floor Drain Backing Up

By June 25, 2021One Comment
basement drain

A basement floor drain backing up is usually due to wastewater looking for a place to escape when there is a problem with the sewer line. The drain connects to the main sewer line. The water seeks the lowest point in the home, and that is the basement. However, this backup is often not even related to the wastewater, but instead to other issues.

Why is the basement floor drain backing up? There are several reasons. The backing up of a washtub basin, or washing machine, tree roots, pipe has deteriorated, bellies in the drain line, flushing of improper objects, or basement drain and trap dry out.

Let’s take a look at why you need to know how to fix a basement floor drain that is backing up, how to prevent future backups, cleaning up the mess, other areas to think about, and when to call a professional.

Why You Need to Know How to Fix Basement Floor Drain Backing Up

It is important for you to know the reasons and how to fix a basement floor drain backing up because you don’t want the smell and moisture in your home. There are some things you can do as the homeowner to fix any issues, while there also may be things you need to call a professional to do.

washing machine and hose

Reason 1: Backup of a Wash Tub Basin or Washing Machine

Not every home has a washtub basin but if you do, this can backup. A washtub basin is in the basement or laundry room and looks like a sink and used for soaking clothes. It could be that sediment and debris have clogged the drain. A washing machine can have the same issue, but it may be in the hose.

How to fix it: You can use a plunger to try to unclog it if it is possibly sediment or debris. If this doesn’t work, you may need to take out the drain to clean it and use an electric snake. This may not be easy to do and require assistance. The other thing you can do is install a strainer on the drain if you don’t have one. If none of these solutions work, contact a professional for help.

Reason 2: Tree Roots Can Cause Basement Floor Drain Backing Up

Tree roots like moisture and they will find it in the sewer drain line, especially when there are cracks. Unfortunately, they don’t care that it is a sewer line and will continue to grow. The tree roots will need to be removed by a professional.

How to fix it: Have a sewer scope inspection done to see if there are roots in your sewer line, blockages, or broken pipes. This costs about $125-300. A drain cleaning machine may be able to help clear the roots away as well by blasting away all the sediment and other gunk. In addition, you may need to relocate a tree or two and the professional will give you solutions to keep it from happening again.

pipe broken
Broken sewer pipe

Reason 3: Pipe Has Deteriorated

The piping material that the sewer lines are made of can accumulate rust and can shrink. When they shrink, it is more difficult for the water and other sediments in the water to get through. Some older homes may have clay or concrete piping and these will start to fall apart over time.

It is important to have a professional check out the type of pipes you have and make a recommendation for what to do next if there is an issue.

How to fix it: Often, it may require replacing the pipes depending if it is a small part of the pipes or a larger section. It will also depend on where the pipes are, as the city is responsible for some of the repairs. The city is responsible for the ones that start at the main underground sewer pipe and are past your property boundaries. This is the main sewer line.

Reason 4: Bellies in the Drain Line Can Cause Basement Floor Drains Backing Up

This is when there is a dip or flat spot in the drain line and happens when the ground settles.

How to fix it: A hydro jet is good to use to keep the line from clogging but if you need to replace the line, a mini excavator may need to be used to dig it up and replace it.

wet wipe in toilet

Reason 5: Flushing of Improper Objects

Sometimes kids will play with toys around the toilet and the toys fall in, without the parent knowing. Other times, feminine products, napkins, paper towels, or baby wipes will be flushed and can clog the drain and back up the system. Did you know that some types of toilet paper also will clog the toilet and can back up the drain? It is better to use one-ply toilet paper as it dissolves better in the water than two-ply toilet paper.

How to fix it: Don’t flush any of the above down the toilet, and use one-ply toilet paper, if possible. I know, that might be a tough sell to your family! If a toy or something important is in there, scoop out the water from the toilet bowl with a disposable cup. Then, if you see the object, with gloves on, pull it out. If not, use a plunger, an auger, snake, or a de-clogger.

Here is a great video about how to fix a clogged toilet when there is an obstruction.

Reason 6: Drain and Trap Dry Out

If you don’t have water flowing through the drain or trap, they can dry out and cause sewer gases to escape. This doesn’t only happen in the basement drain, but also in sinks and drains in the bathroom or kitchen. You might have a shower in the bathroom in the basement that smells and it can be due to a P-trap that is dirty or missing to name a few.

How to fix it: Add water to the drain and the trap and this should help. If the trap is missing, you will need to have one added. A professional can help figure out the issue.

Great video that explains why the basement drain backs up:

How to Prevent Future Backups

  1. Maintain the basement drain as well as other drains in the home. This can be done by scheduling drain cleaning maintenance with a professional.
  2. Drano can be harsh on the pipes so anytime you have a clog, you can do the following, which is safe.
  • Use ½ cup of baking soda and ½ cup of distilled white vinegar.
  • Pour these in the drain.
  • Put a stopper over the concoction and keep it there for 30 minutes while a foam forms.
  • Once 30 minutes is up, take the stopper out and use a plunger.
  • Create a seal with the plunger and move it up and down several times to try to get the clog out.
  • Then, run warm water in the drain for a couple of minutes.
  • Repeat the steps of the plunger and the water if the clog remains.

Cleaning Up the Mess

If the basement drain is backing up and there is a sump pump, hopefully, it will capture all of the water and the basement will dry out. However, you will probably need to mop up the mess or use a shop vac. In addition, depending on what is in the backup, you will need to sanitize the area. If it is a large mess, contact a professional.

Other Areas To Think About

If you have a sump pump, make sure the sump pump is draining efficiently in the yard. The water should be flowing away from the home and not sitting in the yard. If you find that it is not, there may be issues with the grading and drain system. This will require a professional to look at it.

While you are in the home, you may notice a sink in the basement or one of the other floors has water underneath. It can be the sink trap that is leaking. This can be fixed by tightening the connection or taking the trap apart.

Another area you might notice with water around it is the base of the toilet. This can be due to the t-bolts and they should be in place. If not, they need to be fixed. It also could be the wax ring or caulking is needed.

You don’t want to leave the water backing up too long in the basement as it can be contaminated, smell, and cause mold or other things to grow in the area. If you do find mold, you will want to make sure the backup is fixed first. Then put on protective gear to clean up the area if it is less than 3×3 feet. If it is a bigger area, call a professional.

When to Call a Professional

Call a professional if you are unsure what is causing a backup in the basement floor drain. If it is something that you can fix, that is great! If not, contact a professional. Sometimes issues will disguise themselves and you need to find out what the real problem is. Messing around with plumbing and drain lines is something that may need to be left to a professional.


Finding the basement drain is backing up is not fun for any homeowner. Unfortunately, it can be a variety of things that are causing it, and getting to the root of the problem may be difficult. There are a lot of areas that it could be in the home and it will take investigating to find them. Avalon Home Inspections will check your basement drain during a home inspection in Atlanta, GA., and Greenville, SC.

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