Few calls are more stressful than the one we received from a homeowner in West Chester, PA, near West Chester University — home of the Rams. She was panicked because water was pouring out of her toilet, flooding the bathroom, soaking the hallway, and then breaking through the ceiling into the first-floor dining room below.
By the time our team arrived, contaminated water had affected multiple levels of the home, including hardwood flooring, ceilings and even into the unfinished basement. This wasn’t a simple plumbing issue, it was a sewer backup that required professional handling from start to finish. Situations like this happen more often than homeowners realize, especially in older neighborhoods, and understanding why toilets overflow, and what to do next, can make a major difference in limiting damage and health risks.
Why Toilets Overflow in the First Place
Toilets don’t overflow randomly. In nearly every case, there’s a blockage or failure somewhere in the system.
Common causes of toilet overflows include:
- Clogged sewer lines (main line or branch line backups)
- Flushing items that don’t break down properly
- Tree root intrusion into underground sewer pipes
- Older plumbing systems with reduced pipe diameter
- Partial blockages that worsen over time
In this West Chester home, the toilet overflowed because the sewer line was clogged, causing wastewater to back up through the lowest exit point — the toilet.
Why Sewer Backups Are So Dangerous
When a toilet overflows due to a sewer issue, the water involved is classified as Category 3 water — the most hazardous type of water damage.
Sewage-contaminated water can contain:
- Bacteria and viruses
- Pathogens harmful to humans and pets
- Contaminants that soak into porous materials
This is why homeowners should never attempt to clean sewer water themselves. Even brief contact can pose serious health risks, and improper cleanup can allow contamination to remain hidden inside walls, flooring, and ceilings.
What to Do Immediately When a Toilet Overflows
If sewage is coming out of a toilet, time matters, but safety comes first.
The right steps to take:
- Stop using all plumbing fixtures immediately
Running water can worsen the backup. - Contact a licensed plumber to identify and clear the blockage.
- Avoid contact with the water — do not attempt cleanup.
- Call a professional water damage company experienced with sewer backups and emergency water damage.
In this case, once the homeowner’s plumber cleared the sewer line, our team stepped in to handle the damage safely and correctly.
What Professional Sewer Cleanup Actually Involves
Sewer damage cleanup is far more than water removal.
At this West Chester home, our work included:
- Water extraction from affected rooms and ceilings
- Removal of contaminated materials, including portions of ceiling, walls and flooring
- Disinfection and sanitation of all affected areas
- Structural drying to ensure moisture didn’t remain trapped
- Steps taken to prevent future mold growth
- Assistance with insurance claim documentation
Without proper removal, disinfection, and drying, sewer damage can lead to long-term health issues and structural problems.
Why Sewer Damage Often Spreads to Other Floors
Many homeowners are surprised when a toilet overflow damages areas far from the bathroom.
When sewage backs up:
- Water can travel through floor systems
- Ceiling and wall cavities can trap moisture
- Damage may not be visible right away
In this situation, wastewater from the second floor traveled down into the first floor and basement areas, damaging ceilings and hardwood floors along the way.
Why Sewer Overflows Are Never “Just a Plumbing Issue”
Toilet overflows caused by sewer backups are serious events that require immediate, professional attention. What starts as a plumbing problem quickly becomes a health and safety issue, especially when contaminated water spreads through multiple levels of a home.
If you experience a sewer-related toilet overflow, it’s important to act quickly, protect yourself, and bring in qualified professionals who understand both the cleanup and the long-term risks. Emergency water damage involving sewage should always be handled properly the first time to avoid bigger problems later. And at MSI we’ve been handling emergency water damage restoration jobs in Philadelphia, Delaware County, Montgomery County, Bucks County, Camden County New Jersey and Delaware since 1998, so you can trust our team will get it done right the first time.