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What to Pour Down Drain to Kill Roaches?

The American cockroach, aka Palmetto bug and oriental cockroaches, can infest homes through drains.

They are the sturdiest roaches out there and love to live, feed and breed in sewer holes.

The cockroaches infest the home at night by crawling through drain pipes. This is because mostly at night, the drains are not being flooded with water.

What to pour down drain to kill roaches? To kill roaches down the drain, you can use hot boiling water or a concentrated bleach solution.

White vinegar mixed with baking soda will also kill the roaches down the drain. Ammonia or concentrated acid cleaners are other excellent alternatives.

Sometimes it can be challenging to eliminate roach infestation.

The bugs keep reappearing even after successful extermination.

One of the critical reasons for the reinfestation is the poor lookout for the buffer zones. (e.g., drain holes of the sewerage system).

The extermination to be successful, you must always keep these points into special consideration.

Before you read further, just a quick question. Tired of cockroaches and looking for a permanent solution?

Stop wasting your time, invest in these products and follow this guide: How to get rid of roaches? You will be roach-free in 10-20 days.

1. Max Force Glue Traps
2. Advion Gel Baits
3. Harris Powder Bait
4. Gentrol Insect Growth Regulator
5. Loctite Foam Sealent


Optional Items
1. Gel Bait Professional Gun
2. Torch
3. Powder Bait Puffer
4. Insecticide Spray to kill a reveled colony in a single shot

Do Roaches come up through drains?

I wondered how cockroaches managed to infest my bathroom and kitchen a few years back despite taking severe preventive measures.

I constantly searched for cracks, ventilation points, and, loose drain covers. But to my surprise, every time, all seemed to work perfectly fine.

One day by surprise, I managed to see it by myself. Interestingly, the roaches squeezed themselves out from a small hole in the sink cover.

Finally, I realized that although the roaches may look rigid, they have very flexible bodies.

Do roaches come up through drains? Yes! Roaches come up through drains, especially at night, by crawling through the drain pipes.

The roaches love to live inside sewerage holes because of the warm moist environment, ample food in the form of filth, and excellent hiding places.

Moreover, Do roaches die when they go down the drain? Depending upon the species and size, the roaches can survive up to 4 to 6 hours without oxygen.

This makes them least likely to get killed when you flush them down the drain.

The roaches will be back soon to your bathroom once they get to the sewer hole. Therefore, Before flushing the roaches down the drain, make sure to kill them.

Bathroom infestation can be a problem difficult to overcome. I have written a complete article on this and will help you overcome infestation. Please read it here (A Palmetto Bug is hiding in my bathroom!)

Things you can put in the drain to kill roaches

It can be tricky to select an appropriate roach killer that will manage to kill them down the drain.

The most crucial factor that will influence your success in killing roaches down the drain is time.

You can use these methods any time, but my personal experience suggests that these methods are most effective around midnight.

If you surely want to get rid of roaches down the drain, I recommend setting the alarm for midnight. It will be easy if you prepare items beforehand.

1. Boiling Water:

The boiling water is very effective at killing roaches down the drain and is a straightforward solution.

The water will instantly kill the roaches on contacting them. It is essential to know that you may need to repeat this a few times to get the best result.

Always make sure to keep yourself safe. Try to use heat-resistant gloves to avoid burns and scalding of the skin.

For this method to be effective, all you have to do is boil approximately 2 gallons of water. Next, pour the water instantaneously down the drain at once.

Try to avoid breaks because the roaches might escape, sensing danger. Wait for 10 to 15 minutes and then flush the drain with normal water.

2. Bleach Solution

Bleach is another excellent alternative to boiling water. The free chlorine is an oxidizing agent and will kill roaches and destroy their eggs instantaneously.

I recommend bleaching tablets over a pre-packed bleach solution. Using bleaching tablets gives you the freedom to adjust the concentration of the solution.

To make a solution, take 20 bleaching tablets and mix them in one liter of water. This will give you a very concentrated solution. It is essential to use a freshly prepared solution; otherwise, it will lose its efficacy.

Once the solution is in your hands, pour it inside the drain and wait for 20 minutes.

After that, flush the drain with normal water.

You can also use a bleaching solution if you don’t intend to use tablets. All you have to do is to pour 2 cups of solution and flush it after 20 minutes.

Bleach can be corrosive to drain pipes and porcelain, so flush it with water after 20 minutes. Repeat the process if necessary.

Using boiling water mixed with bleaching tablets gives superior results than either alone.

3. Vinegar and Baking Soda

Vinegar and baking soda are readily available at home and effective for killing roaches but are not superior to bleach.

To use vinegar and baking soda for killing roaches down the drain, Mix equal parts of both in a container.

Next, Pour this solution directly into the drain and wait for 5 minutes before you flush normal water over it.

Vinegar is acid and is corrosive to porcelain tiles. Although it can be suitable for old tiles, I do not recommend it for new tiles.

4. Pour Ammonia Down Drain for Roaches

The working principle of ammonia solution is similar to bleach. Both are equally effective at killing roaches down the drain.

The problem with the ammonia solution is its pungent smell, making it less ideal.

For best results, Boil 1 gallon of water and add 2 cups of ammonia solution to it. Pour it down the drain and wait for the results.

Can Roaches come out of shower drains?

The factor that keeps roaches from coming out of the drain is standing water inside the drain pipes.

The water creates a barrier that cockroaches can’t cross. This is why cockroaches cant come out from the commode.

On the other side shower, kitchen, and other drains lack a water barrier making this route ideal for roaches.

The tiny holes on the drain cover will prevent bathroom and kitchen infestation depending upon the size of the roaches.

Palmetto bugs, including American and Florida wood cockroaches, will usually find it challenging to escape tiny holes on the drain cover.

Still, smokey brown and german cockroaches will easily come out of shower holes.

The roaches usually come out at the ideal time around midnight when drains are usually not used and flooded with water.

Baby palmetto bugs are small in size, and they will escape the most miniature drain covers available on the market. Read more about Baby Palmetto Bugs here.

Do palmetto bugs come up through drains?

Palmetto bugs usually enter bathrooms through wastewater drains.

Since drains are directly connected to the sewer system, American Cockroaches, a.k.a palmetto bugs, are extensively found there.

So they find a way to pop up through the drain holes, even if they have to swim through the commode S trap.

They can also come through another hole or a gap in walls, doors, windows, etc.

Generally, roaches keep wandering in search of an ideal environment with plenty of food, a lot of humidity, and ideal warmth.

Bathrooms are humid and warm but a little scarce of food, although the tissue paper laying around is no less than a healthy meal they are looking for.

A palmetto bug can also land in your bathroom from somewhere else, like your kitchen or your room, but the drain theory is most of the time why you have it.

Additional Read: There is a palmetto bug in my bathroom!

What liquid can kill cockroaches?

If you are looking for cockroach-killing products, then these are the best ones money can buy. Don’t waste your time and get one of these to eliminate all your roach problems.

– Bengal Roach Killer is the best spray to kill a cockroach
– Advion Cockroach Gel Bait is the most effective gel you can buy
– Hot Shot Liquid Cockroach Trapper and Killer is the best trap you can get for cockroaches
– Combat Max 12 Month Roach Killing Bait is the best bait out on the market
– Ortho Home Defence Max Killer is the ultimate choice to get rid of all types of cockroaches

How do you keep roaches from coming up drains?

The drains can be a source of roach infestation in the majority of cases. For the extermination to be successful, we must keep an eye on our drains. There are a

few steps that, if carefully taken, will prevent a roach infestation from occurring through drains.

  1. Use bathroom drain covers with smaller holes. This will prevent roaches from coming out of holes.
  2. Prefer using anti-odor drain covers. They can be closed once the bathroom sink or basin is not being used.
  3. Roaches are attracted to filth so it’s better to keep your bathrooms clean and cabinets closed.
  4. In case of heavy infestation, use hinged floor drain covers which temporarily close the drains when not being used.
  5. Use boiling water or bleach solution to kill roaches down the drain.
  6. Observe for cracks and crevices inside the bathroom.

You can also use natural palmetto bug repellents for kitchen infestation.

Can you Pour Borax Down Drain for Roaches?

Boric acid and borax are water-soluble. So pouring them into the drain will yield no results, and it must be consumed for boric acid or borax to kill roaches.

Using other methods like disinfecting drains with Ammonia, Bleach, or drain cleaning acids is better to get rid of cockroaches in drains.

Additional Read: