What To Pour Down The Drain To Kill Roaches Instantly?

Roaches that come out of the drains are sewer roaches. 

Two types of roaches fall under the category of sewer roaches. They’re American cockroaches and oriental cockroaches.

In this guide, you’ll find what to pour down the drain to kill roaches.

The best part?

You don’t need a pest controller to do it. 

With a little bit of precaution, you can do it by yourself.

Let’s dive in.

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What Are Sewer Roaches?

Cockroach in a bathroom drain

Before you find out what to pour in the drain to kill roaches, let’s check out what are these sewer roaches.

Or what types of roaches live in the drains.

Sewer roaches are types of roaches that can thrive and breed in wet filth. 

American roaches and oriental roaches are the two types of roaches that can do it.

And hence, they’re categorized as sewer roaches.

If you observe the poop of sewer roaches, you’ll find it like a smear mark. It’s wet because they consume the waste in sewers and drains.

In contrast, feces of other common home roaches, like the German cockroach and the brown-banded cockroach, are dry and hard.

It’s because they prefer to live in dry places and consume dry waste.

The drains are a perfect place for sewer roaches to establish their colonies, especially when the drains are clogged.

There’s enough dampness in the drains to keep the roaches alive.

And most importantly, the wastes that clog the drains are food for these roaches.

But there’s a catch. 

Dry drains can also be home to many roaches. In that case, other types of cockroaches that don’t prefer to live in moist places can make these dry drains their home.

Dry drains are pretty common in homes that are lying vacant for quite some time. 

If you don’t frequent any bathroom or any room in your home with water exit drains, the drains dry up. 

Those dry drains make it an ideal home for roaches like the German roach and brown-banded roach that prefer to live in dry and warm places.

Can Cockroaches Come Up The Drains?

what to pour in the drains to kill roaches

Yes, cockroaches can come up the drains. 

Cockroaches are nocturnal scavengers. 

It’s in their nature to keep looking out for wastes to eat. 

That’s the reason that you’d see roaches in the bathroom at night.

Sewer roaches will come up the drains and crawl on the bathroom floor, sink, and kitchen looking for organic waste, like your hair and nails, food wastes, and food stains to eat.

So, how do they crawl out?

They crawl out through the drain holes and when there’s no appropriate drain cover. 

Most sinks in the bathroom, kitchen, laundry room, and basement don’t have drain covers.

That makes it easy for roaches to sneak out of the drains during the night.

So, next time if you see roaches in the bathroom at night, be sure that the problem may lie in the drains.

What To Pour Down The Drain To Kill Roaches?

Now that you know what types of roaches are in the drains and why they crawl out of the drains, it’s time to put an end to it.

Thankfully, you can do it without the help of any pest controller. 

The three things that you’d need to pour down the drains to kill the roaches might be there in your home right now.

So, here are the three things to pour down the drain to kill roaches –

  1. Bleach
  2. Baking soda
  3. White vinegar
  4. Ammonia cleaner

Pour Bleach In The Drain To Kill Roaches

Will Bleach Kill Bed Bugs On Hard Surfaces

Bleach is a lethal cockroach killer. It’s a handy drain unclogger too! 

And it must be lying there right now in your home.

Pour half a cup of bleach in the bathroom drains, bathtub drain, and in the sink drains of your kitchen, laundry room, and basement.

Let it sit for 15-20 minutes, at max.

Bleach is corrosive. Let it sit in the drains longer than 20 minutes can damage the drain pipes.

Then pour a few cups of hot water into each of the drains.

And there you go, you not only killed all the sewer roaches hiding in the drains, but also you unclogged the drains.

Do keep in mind to wear gloves while pouring bleach. 

Direct contact of your skin with bleach can harm your skin.

Pour A Mixture Of White Vinegar And Baking Soda In The Drain To Kill Roaches

A great alternative to bleach is a mixture of vinegar and baking soda.

Mix equal amounts of baking soda and white vinegar in a cup. 

Stir the mix well. Pour it in the drains.

Let the mix sit for no longer than 5 minutes.

Then as a final blow, pour hot water into the drains.

That’ll eliminate all the roaches hiding in the drains.

To add more punch to the mixture, you can also mix salt with it.

Pour A Mixture Of Ammonia And Hot Water In The Drain To Kill Roaches

Another potent roach killer is ammonia. 

Ammonia cleaner is water-soluble, and it mixes with water fast.

Mix equal amounts of water and ammonia cleaner in a bucket. 

And pour the mixture into the drains to kill roaches.

Ammonia also kills roaches on contact. 

If you want to make a homemade roach spray, pour the mixture into a spray bottle.

And spray it directly on the roaches that you come across. 

It’ll kill the roaches instantly.

Pro Tip – Use an anti-roach drain protector to cover all types of drains in your home, including shower drains, bathroom drain, bathtub drains, and sink drains.

And, clean the drains often. Don’t let the drains remain clogged for days.

Should You Pour Borax Down The Drain To Kill Roaches?

In all honesty, pouring borax down the drain to kill roaches can give you an unsatisfactory result.


It’s because borax or boric acid is not an instant roach killer.

Though boric acid is a termite killer, roaches take 72 hours to die when they ingest it.

Mixing borax with water will make it lose its potency more, and on top of it, the roaches might not ingest it.

It’d be best to use ammonia, bleach, baking soda, and vinegar to kill roaches in the drains.

Ammonia, vinegar, baking soda, and bleach also eliminate drain flies that hide in the drains.

Is Pouring Chemicals Down The Drains Is A Solution To Cockroach Infestation In Your Home?

In brutal honesty, NO.

Whatever you’ve found out till now works well to stop roaches coming out of the drains. But temporarily.

Remember, cockroaches are hard to eliminate.

Physical sighting of one cockroach in your home is a strong enough indication of a possible roach infestation running deep inside your home.

Also, relying on these chemicals as the only way to get rid of sewer roaches can cause serious harm to the drains.

They can cause leaks and bursts in pipes. 

Repeated usage of these chemicals also creates deposits in the drains that can cause clogging deeper down the drains.

And the worst part, these chemicals mix up with groundwater, which causes damage to the environment.

So, it’d be best if you use these chemicals as a stop-gap measure to kill roaches and bugs coming out of the drains. 

Remember, it’s always best to hire a pest controller when it comes to getting rid of roach infestation in your home. 

Most natural and DIY ways work well on tough bugs like roaches and bed bugs when the infestation level is low. 

When the infestation level is severe, always hire a professional.


There are 4 things to pour down the drain to kill roaches –

  1. Bleach 
  2. Baking soda
  3. White vinegar
  4. Ammonia cleaner

In this guide, you found out what types of roaches reside in the drains, why you see them in the bathroom and kitchen sink, and most importantly, the side effects of using chemicals in the drains.

Remember, cockroaches coming out of drains can be a sign of roach infestation running deep inside your home. 

For more in-depth information check our ultimate guide on eliminating roaches in your home.