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Why Is My Basement Drain Backing Up? [8 Ways To Fix It]

Basements are likely to have the worst drainage problems. If your basement is frequently flooding or waterlogging, it’s time to address the issue.

Why is the basement drain backing up?

There can be many reasons behind this problem. Low-lying plumbing fittings, flushing improper objects, or even tree roots can block your drain. Sometimes the washing machine or washtub basin can be responsible for this. Cleaning the drains solve the problem easily. Or, you can just call in a professional.

If you can relate to these problems, we have the solution for you. This article contains the procedure to fix this problem in the easiest way possible.

Without any delay, let’s get into this!

8 Reasons Why Basement Drains Can Back Up

Drain backups occur when hair, soap scum, and other debris plug the drains in your basement. By utilizing drain care solutions on a daily basis, it will surprisingly be easy to avoid. 

This article will lead you in the correct way for restoring order to your basement.

Reason 1: Low-To-The-Ground Plumbing Fixtures 

The first place you’ll probably notice a backlog is in any basement showers, bathtubs, or toilets. Though there are different types of PVC connections, these are low-lying plumbing fittings. However, these are not often the source of the problem.

The main problem happens when water backs up behind the fixture, forcing it to flush continuously.


Don’t attempt to repair the backlog until you are certain there is a blockage in one of these fixtures. If you observe a considerable dip in the toilet bowl or shower drain, it’s a sign.

You might see water pooling in the bottom of your basin with no noticeable increase of flow. That’s when you know it’s time to call in an expert.

Reason 2: Wash Tub Basin Backing Up

This is when you have a drain backlog in your basement. It’s possible that the cause is your washtub basin. Cleaning the strainer on the drain input may be a faster fix if you do it yourself.


You may use a plunger to remove the sediment and debris from the trap beneath the basin. A snake auger may be necessary for the absence of a plunger. Or the trap may need to be removed and cleaned.

Professional plumbers can use their skills and experience to remove blockages that are deeper down the system. They can avoid causing more harm to your plumbing if the obstruction is not easily accessible.

Reason 3: Washing Machine Backing Up

Washing machine backups waste a lot of water. As well as costing you money, there can also be an impact on your house’s foundation. Luckily, the problem can be remedied with a few simple actions.


Check the strainer on the drain line after turning off the washing machine. Before reattaching, clear away any obstructions. And then, check for any loose fittings under the sink. These can cause water to back up into the washing machine and overflow down the drain pipes.

If fixing loose fittings under the sink doesn’t solve the problem, it’s possible that there is a clog in the trap. Or the clog might be farther down the drain. It’s best to hire a professional if cleaning the trap doesn’t work. 

Reason 4: Issues With Main House Trap

The main house trap keeps sewage gases out of your house.

With this setup, there is a plug on the home end of the line. Another on the street side of the line. Removing these plugs at random is not suggested. Since it may allow sewage effluent to enter your property. The plugs are also incredibly tough to replace.


To enable the backup to drain away from your home, open (without removing) the street-side outlet first. Then the house-end plug.

Even yet, this technique is dangerous and should only be performed by a professional plumber.

Reason 5: Floor Drain Clogs

The floor drain joins the house drain, which is located under your basement. It usually stays dry because it’s there to drain excess water from your basement.

Clogs and excessive rainwater, on the other hand, might cause the drain to back up. This can be in the drain, the home trap, or the sewage main. As a result, the basement drain can also back up after a shower.


You can fix this by clearing the blockage from your floor drain. Then re-route a part of your house’s water pipes. The two drains should connect to a new location. 

If you’re unsure about what to do, or if the clog persists, call a sewer professional. He will determine the source and location of the obstruction.

Reason 6: Tree Roots Interference

Roots want moisture. And they can find it in the sewage drain pipe, particularly if there are fractures. They don’t seem to mind that it’s a sewer line, and it’ll only keep growing. 


Have a sewage scope check done to discover if there are any roots, obstructions, or damaged pipes. A drain cleaning equipment may be able to help clear out the roots. They can blast away all the silt and other gunk.

You may need to relocate one or more trees. The specialist will provide you with ways to prevent this from happening again.

Reason 7: Flushing Improper Objects

When children play with toys near the toilet, the toys may fall in without the parents’ knowledge. Flushing feminine items, napkins, paper towels, or baby wipes can be other reasons. These might block the drain and cause a backup. 

It’s preferable to use one-ply toilet paper over two-ply toilet paper. Because one-ply toilet paper dissolves easier in water.


Avoid flushing any of the aforementioned items down the toilet and, if feasible, use one-ply toilet paper. We understand how difficult it would be to persuade your family of this! 

If there’s a toy or something essential, use a disposable cup to scoop the water out. Then take it out while wearing gloves. If it doesn’t work, try a plunger, auger, snake, or a declogger.

In case you don’t know where to find a de-clogger, we have picked some for you:

Product 1
Product 2

These de-cloggers perform really well. You will surely not be disappointed with their performance.

Reason 8: Dried Out Drain and Trap

If water isn’t flowing down the drain or trap, it might dry out, allowing sewage gases to escape. This happens not just in the basement drain, but also in the bathroom, kitchen sinks, and drains. 

You could have a stinky shower in the basement bathroom. This might be caused by a filthy or missing p-trap or s-trap, to name a few possibilities.


This might assist if you pour water down the drain and into the trap. You’ll need to have one installed if the trap is absent. A specialist can assist you in determining the problem.

There you go! These were the most prominent reasons behind basement drain backing up. Drain clogs that aren’t properly investigated might lead to more issues. And thus cause possible damage to the pipelines.

Leave the diagnosis to the specialists if you don’t have enough experience. They’ll do a visual check of your basement drains using a high-tech video snake. They can then clear the blockages or make any repairs that are required.

Tips To Avoid Backing Up Basement Drain

You might be thinking about building a new basement drainage system. Here are some ideas to assist you to avoid a future basement flood:

  • You can use rubber drain covers. This will allow water to pass through and away from the home from the ground outside.
  • Inspect your home for plumbing leaks,
  • Install a sump pump near the lowest point of your basement floor, where moisture is most likely to collect.
  • Maintain the basement drain as well as the rest of the house’s drains. 

These tips should come in quite handy if you’re planning on building a new basement drainage system.


Question: How much does it cost to unclog a basement drain?

Answer: Unclogging a drain can cost anywhere from $75 to $550. This depends on hourly rates, accessibility, severity, and the reason for the clog.

Question: Is it necessary for me to snake my own drain?

Answer: Snaking your own drain can be done for lesser obstructions. Hairballs or food remains to cause small sink blockages. A light-gauge, hand-operated auger can be used to clear them.

Question: Is it possible for tree roots to harm the foundation of a house?

Answer: Tree roots may wreak havoc on a home’s foundation if given the opportunity. Tree roots are opportunistic, only growing and penetrating where conditions are favorable. Such as friable soils and mulch.

Bottom Line

That’s it all! You should not be bothered with your basement drain backing up anymore. If you still have any queries, feel free to ask. We’re always ready to hear.

Till then, best wishes!