When your floor drain overflows, raw sewage flows back up the pipe and into your basement. Fixing the issue requires a plumber to correct, and the smelly mess left behind can require professional cleaning if the flooding is severe.
In this article, we’re going to walk through the cause of drain backflow, how to fix it, and how to clean up light sewage flooding.
If your basement floor drain backs up when the toilet is flushed, it’s caused by a blockage in your home’s sewer line. The most common source of these blockages is flushing items that aren’t meant to be flushed, but tree roots invading the sewer line can also cause blockages. This is not a DIY fix.
Dumping chemicals or trying to unblock the drain yourself can cause serious damage to the city’s sewer system – and you would be on the hook. Leave this one to the professionals.
There are a few causes of floor drain backups. We’ll go over those, as well as a few steps you can take before you call a trained professional.
Floor Drain Backup – Causes
Usually, backflow in your basement floor drain is caused by non-flushable items sent down the toilet. Even if they make it down the toilet successfully, they often clog the main sewer line between your home and the city’s sewer system.
It’s extremely important to only flush toilet paper and human waste down your toilet.
These are a few examples of commonly flush items that should never be flushed:
- Paper Towels
- Facial Tissues
- Pads & Tampons
- “Flushable” Wipes – These are NOT FLUSHABLE. No matter how much the labeling says they are, these do not break down like toilet paper and can cause serious blockages.
- Prescription Medication – This one won’t cause blockages, but you still shouldn’t do it. It can pollute the water and impact the wildlife. Call your local pharmacies to find one with a drop-off bin for unused medication.
This list is far from exhaustive. Unfortunately, many people use their toilets as an extra waste basket. Sewage systems are only designed to handle raw sewage and toilet paper – and if there’s a blockage, that sewage is coming back up the floor drain.
Blockages aren’t always your fault, though.
As disgusting as it may be, raw sewage is full of nutrients. Trees love it and their roots will seek out the moist sewer line, looking for any entrance. Once they’re inside, they just continue to grow – eventually catching hold of toilet paper and normal sewage until the pipe and drain are completely blocked.
Preventing Further Floor Drain Backup
The main water line is where all the water flows into your home from your city’s water supply. Where the sewage line is the Out, the main water line is the In.
The sewer line connects all the drains in your house to the sewer system – it can get messy when it’s blocked. If someone is trying to take a shower or flushes the toilet, the basement floor drain is the lowest unblocked point of exit.
To turn off your water supply, you need to locate the shut-off valve. It should be inside your home, usually around the perimeter on the street side. If it’s proving difficult to find, the property inspection report that was completed when you purchased the house should have the location listed.
Alternatively, call your local water company. The main water line has another shut-off valve at the street level. Sometimes you can turn it off yourself, but other times it requires an emergency dispatch team from the company.
Locate The Sewer Cleanout Pipe
Plumbers will need to access this pipe to unclog the sewer line. By preemptively finding it, you can save time that the plumber might charge for.
The sewer cleanout pipe is usually in the backyard, but in colder climates it may be inside the home or garage. To find yours, walk around your house looking for a pipe jutting straight upwards. Usually, these are white or black PVC.
Since it isn’t used often, it may not be immediately apparent. Check under bushes and other overgrowth that may be covering it.
In colder climates, the sewer cleanout line may be located indoors. In these cases, it will usually be a good distance away from living spaces – garage, basement, and utility closets are all common.
Once you’ve located yours, remove the cap if possible. This should relieve some pressure in the sewer line.
Call A Plumber
As we said before – this is NOT a DIY fix. A plumber has the tools and knowledge needed to unclog your sewer line safely. They use a relatively simple process.
Using the sewer cleanout pipe, they thread a camera on a snake into the piping to locate and identify the blockage. If it’s a minor blockage, caused by thick or large amounts of toilet paper, a plumbing snake is usually sufficient to unclog it.
A hydrojet is the solution for more serious blockages. This high pressure water jet can cut through most non-flushable items, but must be used with care to prevent damage to the pipes.
What A Plumber Might Do
If the blockage is caused by root systems invading the sewer line, they may use specialized chemicals to kill the root systems. This can be the most expensive issue, with severe cases requiring the replacement of pipes.
While it is possible to buy these tools as a consumer, we don’t recommend you trying to tackle this problem yourself. Misusing these tools can cause damage to your sewer line, which can end up being way more costly.
When speaking with the plumber, inquire about the cost of installing a backwater valve in your basement floor drain. A backwater valve will seal the drain when sewage begins to back up, preventing a messy cleanup.
Cleaning Up After Your Basement Drain Backs Up
The basement floor drain blockage has been removed – and now it’s time for the cleanup. If it was a serious flooding event that flowed up the walls, there may be hidden electrical damage. In these cases, consult a professional cleaning crew to avoid unnecessary risk.
If it’s a small flood that didn’t reach walls with running electricity, it should be safe to clean it up yourself. Wear clothing that you are okay with getting rid of, as well as goggles, a facemask, and gloves.
From personal experience, I can say – raw sewage splashing on your face is unpleasant.
Open any windows in the flooded area and set up fans. This not only helps to dry up the liquid, it also helps to clear out any noxious gasses from the sewage. Be sure you have good ventilation and airflow.
Remove any physical debris or sewage remains. I recommend using a separate broom and dustpan from the one you regularly use in the household.
Use a solution of hot water and a low-sud soap to scrub down any surface that came in contact with the sewage flood. Using fresh hot water, rinse them down well afterwards.
Use a mixture of 7-8 Tablespoons of bleach to one gallon of water to sanitize every surface that came in contact with the liquid. Be sure you have good ventilation and airflow.
Dispose of clothing that came in contact with the sewage. Remove your shoes before walking about the house and make sure you clean them well before using them again.
Floor drain backups happen when a blockage in the sewer line prevents toilet water from entering the sewer. The water seeks out the nearest available exit point and flows back up.
This is not usually a DIY fix, as improperly dumping chemicals or using plumbing tools on the drain can damage the city’s sewer system. Turn off your Main Water Line, locate and uncap the sewer cleanout line, and call a plumber.
If it was a small amount of backflow out of the basement floor drain, often you can safely perform the cleanup yourself. More serious floods require a professional, as there may be hidden electrical damage.