5 Easy Ways to Unclog a Basement Floor Drain


Unclogging a basement floor drain is crucial to prevent water backups and potential flooding. Here’s a brief summary of ways to unclog a basement floor drain:

  • Plunger: Start by using a plunger designed for drains. Ensure there’s enough water in the drain to create a seal. Plunge vigorously to dislodge the clog.
  • Boiling Water: Pour a pot of boiling water down the drain. This can help melt and flush away grease or debris causing the clog.
  • Baking Soda and Vinegar: Combine half a cup of baking soda with half a cup of vinegar. Pour this mixture down the drain, and let it sit for 15-30 minutes. Follow with hot water to flush.
  • Mechanical Snake or Auger: Use a drain snake or auger designed for basement floor drains. Insert it into the drain and turn the handle to break up or remove the clog.
  • Chemical Drain Cleaner (Caution): As a last resort, consider using a chemical drain cleaner designed for basement floor drains. Follow the manufacturer’s instructions carefully, and use these products sparingly, as they can be harmful to pipes and the environment.
  • Plumber’s Snake: If you have access to a plumber’s snake, you can use it to reach deeper into the drain and break up stubborn clogs.
  • Professional Assistance: If DIY methods don’t work, or if you suspect a more significant issue in your plumbing system, consult a professional plumber for a thorough inspection and repair.

How a Basement Floor Drain Works

Image courtesy: Nations Home Inspection, Inc

All the fixtures (toilets, tubs, showers, sinks, washing machines) in your house have a separate drainpipe each. All these small drainpipes are then connected to the main house drainpipe which in turn drains to the city’s sewer lines or septic tank.

A vertical pipe is connected to the main drainpipe and runs through the roof of the house. This is called the plumbing vent. It helps in removing sewer gases from the drainpipe and also brings in air which helps in draining.

Since the basement floor drain is located in the lowest point of the house, it drains directly into the sewer line, same as the house drainpipe. This means that if you flushed something that you shouldn’t flush in the toilet, sink or tub, it will affect how the basement drain works.

Hair from shower/tub drains and grease from the kitchen sink can also clog the drain and a result the basement floor drain will start to back up. Most people also make the mistake of sweeping the debris, pet hair and dirt in the basement directly in to the drain.

With times, all this trash will buildup and cause a clog and therefore a backing up basement drain. Don’t therefore be surprised to wake up and find standing water in your basement.

How to Unclog a Basement Floor Drain

Clearing Floor drains (or any other drains for that matter) is not a glorious task. You should therefore dress appropriately for the job.

As a minimum, I recommend rubber gloves, boots and goggles. Make sure to also wear you old clothes so that if something nasty splashes on them you can always toss them away later.

Although there are several ways to clear a clogged basement floor drain, I would suggest starting with the easiest of them all and upgrade gradually.

It is way cheaper to try and unclog the drain yourself than hiring a plumber. To start with, a plumber will first need to run a drain camera which will set you back around $200. And then he will charge you for the actual job.

To gain access to the basement floor drain, start by removing the drain cover using a screwdriver. Once the screws are out you can then just pry it off or grab it using needle-nose pliers and lift it off.

The following are the methods you can use to unclog a basement floor drain:

1. Plunge the Drain

A plunger is an effective tool for clearing drain clogs. It is however limited and will only clear light clogs.

In order to use a plunger, you will need to have standing water around the basement floor drain. This is because the cup of the plunger needs to be immersed in water in order to create a watertight seal.

Also, the drain needs to be full of water in order to generate the required pressure to dislodge the clog.

  • Place the cup of the plunger nicely over the basement floor drain opening.
  • Start plunging gently to engage the plunger to the floor.
  • Plunge aggressively for about 2 minutes.
  • Lift off the plunger and check if the standing water will start to drain properly.
  • Plunge some more if needed.

If the plunger doesn’t seem to do the job, you will need to upgrade to a better tool/method.

2. Use Baking Soda and Vinegar

Baking soda (which is an alkali) and vinegar (a weak acid) will react and break down the clog thereby clearing the drain.

To use this method, you should not have standing water over your drain opening. You need the baking soda and vinegar act directly on the clog.

Usually, the clog will be in the drain trap. which is the U-bend just below the drain opening. More on P-traps here.

If you have standing water, either drain the water first or choose another method of clearing the drain.

Here is how to unclog a basement floor drain using baking soda and vinegar:

  • Pour a generous amount of baking soda down the drain.
  • Slowly follow it up with a cup or 2 of white vinegar
  • Let the solution fizzle for about 15 minutes.
  • Dump a gallon of boiling water down the drain.

Baking soda and vinegar will break down the clog while boiling water will break it down even further and flush it down the drain.

3. Clean it with a Drain Cleaning Bladder

I would suggest that you use this method before trying to unclog the drain using a snake. To start with, a drain cleaning bladder is cheaper than a snake and you are not likely to damage your plumbing as you would with a drain snake.

A drain cleaning bladder is made of rubber and works like a balloon. Here is how it works:

  • Connect it to a garden hose.
  • Connect the garden hose to a cold water faucet.
  • Push the drain bladder inside the drain until you until you encounter resistance (the location of the clog).
  • Slowly turn on the water.

It is important to know that there are different sizes of drain bladders. Smaller ones are used to unclog sink or bathtub drains. The ones designed for basement floor drain are rated between 3 and 6 inches.

Although most drain bladders will work with water, some people opt to connect them to an air compressor. If you decide to do this, do not exceed 50 psi otherwise the bladder will rapture.

  • As the bladder fills with water, it will expand and seal around the inside of the drainpipe. This is important in ensuring that the pressure created will not escape.
  • The drain bladder has a small hole at the front. As more is sent to the bladder, the hole will open and starts shooting water under pressure straight at the clog thereby breaking it down and clearing the drain.

The Drain King drain bladder available here on Amazon is one of the best to buy. Here is a schematic of how it works.


4. Snake the Drain

A drain snake, also known as a plumber’s snake or drain auger is a fantastic tool to clear clogged drains, although not always easy to use by beginners. Please do not attempt to use a toilet auger to clear a basement floor drain.

For this job, you will need a proper drain auger, which even allows you to connect a drill. If not you can still use the provided cranking handle.

A drain snake has a hooked spring-like head and a flexible cable rolled on a drum which is then connected to a cranking handle. The snake head will either hook whatever that is clogging the drain or shred it to smaller pieces which are easy to flush down the drain.

Here is how to use a drain snake to unclog a basement floor drain:

  • Remove the lock from the auger drum to free the cable.
  • Start feeding the cable down the drain until you encounter restriction.
  • Lock the cable on the drum.
  • Slowly start cranking the handle clockwise. If the cable starts to twist instead of turn, change the direction and start again until you go past the restriction.
  • Release more cable from the drum and check if there are more restrictions/clogs.
  • If you are sure the clog has been removed, pull out the snake as you clean it at the same time using a piece of cloth.
  • Dump a bucket of water down the drain just to be sure that indeed the drain is working as it should.

5. Call a Plumber

If you have tried all the methods I have outlined above and nothing seems to work, it is time to call a professional plumber. Plumbers have more experience than you, have more advanced tools and equipment and will have likely solved such problems plenty of times.

Be prepared to part with hundreds of dollars since as I had mentioned earlier and as you already know, plumbers are not cheap.

And basically that is how to unclog a basement floor drain. I hope this guide was helpful.

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