If your basement drain is clogged, find out why it's clogging, how to fix it, and what you can do to stop it from clogging again in the future.

What causes a basement floor drain clog?

Most basements have drainage systems that take unwanted water from the home's foundation, and channel it away from the house. The two most common systems we install are the drain tile system (otherwise known as the French Drain) and the DRY-UP Baseboard waterproofing system.

Improper slope

A common cause of a clogged basement drainage system is improper slope. Oftentimes we see channel systems installed at an incline rather than a decline, or it goes up and down rather than only downwards. Gravity will pull the water to the lowest point, and this can cause clogs.

Debris causing a clog

The most common case of a basement floor drain clog is because debris is blocking the drainage pipe. This could be trash that shouldn't have been thrown down the drain or an assortment of other disposed items, like hair or dirt.

Cheap, outdated, or broken drainage pipes

Sometimes unreliable waterproofing companies will install cheap and non-durable drainage systems. These will inevitably cause issues to arise in the future when large amounts of water need to channel out. Also, if your house is a bit older, the system may just need an upgrade.

Signs of clogged basement drains

If you are experiencing any of the below issues, they could be caused by a clogged basement drain.

Warped basement floor

If your basement floor is curved or slumping in an unnatural way, this could be caused by water being backed up underneath the concrete surface.

Cracks on your basement floor

If your basement floor is experiencing cracking, this could be caused by a clogged basement drain. In this case, the water is pushing up on the basement floor and causing it to crack.

Water comes in when it rains

If your basement leakage occurred after heavy rains recently, this could also mean that your drainage system is backed up and not working properly.

Standing water on basement floor

The most common telltale sign of a clogged basement drain is standing water on your floor.

How to unclog a floor drain

Here are some simple solutions for unclogging a floor drain. Remember, it is always best to consult with a professional before trying any of these solutions.

Snake the drain

A common fix to a clogged basement drainage system is to use a snake to pull out unwanted debris. You must be careful using this method, however, as some basement drainage systems could be damaged by some of the snakes. Again, we recommend consulting with a professional before you risk ruining your drain pipes.

Baking soda & vinegar

Sometimes the ol' baking soda & vinegar trick will work. Simply pour it down the drain, and see if it helps clear up the clog.


A plunger may also do the trick. Simply place the plunger in the entrance of the drainage pipe and have at it.

Other tips

Turn off water

It's important to recognize whether your clog is coming from inside the house or outside. If, say, a laundry machine or leaking interior plumbing pipes are causing the issues, be sure to shut off the water before trying to fix the problems.

Clean up water

If you have standing water in your basement, the first step is cleaning it up.

Dry your basement (mold prevention)

Mold is not good. Be sure to dry your home properly if you've recently experienced water leakage.

Why is my basement floor drain flooding?

As mentioned before, you need to be sure to diagnose your floor drain problem before trying to fix it. There are dozens of reasons why your basement is flooding, and by not understanding the problem before trying to fix them, you are risking "fixing" the wrong problems and causing more severe damage in the future.

One time or recurring flooding?

Another point to consider is whether your basement drain clogs frequently or this was a one-time event. If this happens frequently, we know there is an underlying cause that can be fixed. We also can be sure that if it has happened several times previously, it will probably happen again in the future. This makes solving the issue a high priority, as waiting to fix your clogged drains will cost you thousands in fixes.

Can I pour Drano down my basement drain?

Before pouring Drano down your basement drain, it is important to recognize what type of drain this is and what its purpose is. If this is a sewage drain, then it is probably safe to pour Drano down. If this is another type of drainage system, be sure to check with your local contractor professional to be safe that is will not cause unwanted damage.

How much does it cost to unclog a basement drain?

The price of unclogging a basement drainage system depends on the culprit of the clog. If it is a simple fix, you may end up only paying in the hundreds. If your basement drainage systems need to be upgraded, it could cost anywhere from $2,000 - $20,000 to resolve the issues.

Old house basement drain clogged

As briefly mentioned before, old houses were not always built with high quality drainage systems. They used what were available at the time, but these older houses oftentimes need new basement drainage. As always, consult with a professional before making a decision on fixing your basement drains.

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Written by:
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