A drain that clogs once is annoying. A drain that keeps clogging means something deeper is wrong. Figuring out why your drain keeps clogging is the only way to stop the cycle for good.
Below are the real causes we find on calls across Ajax and Durham Region, plus what actually fixes them.
Why Your Drain Keeps Clogging Over and Over
A repeat clog is a symptom, not the problem. When you plunge or pour cleaner down the drain, you clear the surface blockage but leave the cause behind. So it comes right back.
Most recurring clogs trace back to one of these:
- Grease and fat that cooled and hardened inside the pipe
- Hair and soap scum building up in bathroom drains
- Food scraps that the disposal never fully broke down
- Tree roots growing into an older sewer line
- A pipe that sags or was installed at the wrong slope
The fix depends on the cause. A bathroom sink that clogs monthly is a different problem than a basement drain that backs up every few weeks. Pinning down the source is the first real step.
Grease, Hair, and the Usual Suspects
Most kitchen clogs come down to grease. It pours in as a warm liquid, then cools and sticks to the pipe walls like candle wax. Over time it narrows the pipe until water barely passes.
Never pour cooking oil, bacon fat, or grease down the drain. Let it cool, then scrape it into the trash. Wipe greasy pans with a paper towel before washing.
Bathroom drains are a different story. Hair binds with soap scum into a dense clump that catches everything after it. A cheap drain screen over the shower and sink stops most of it before it ever gets in.
Stop feeding the clog
Small habits make the biggest difference. Keep these out of your drains:
- Coffee grounds and eggshells
- Rice, pasta, and starchy food that swells with water
- Cotton swabs, floss, and wipes labelled flushable
- Grease, oil, and fat of any kind
These do not break down. They settle, collect, and grow into the next clog.
When the Problem Is Deeper Than the Drain
Sometimes the clog is not in the fixture at all. It is in the main line that carries waste out to the sewer. That changes everything.
A few signs point to a main line problem. More than one fixture backs up at the same time. Your toilet gurgles when the washer drains. Water comes up in the basement floor drain when you run the sink upstairs.
In older Oshawa, Whitby, and Pickering homes, tree roots are a common cause. Roots find tiny cracks in the sewer line and grow inside, catching debris until the line clogs. This is not a plunger job. It needs a proper drain cleaning with a snake or a camera inspection to find the spot.
If sewage is backing up into your home, that is more than a clog. It can be a sign you need a backwater valve. Read our guide on whether you need a backwater valve to see if your home is at risk.
How a Plumber Actually Clears a Recurring Clog
Store-bought drain cleaner is a short-term patch at best. The harsh chemicals can also eat away at older pipes and make the real problem worse.
A licensed plumber clears the clog at the source instead of the surface. We start with a drain snake to break through and pull out the blockage. For a stubborn or repeat clog, a camera inspection shows exactly what is going on inside the pipe, whether that is roots, a sag, or years of buildup.
Drain snaking starts at about $99. A typical full drain job runs $250 to $350, depending on the location and how bad the blockage is. You get a flat quote before we start, so there are no surprises. Our drain cleaning service covers everything from a slow sink to a backed-up main line.
For a full breakdown of what plumbing work costs in our area, see our Durham Region plumbing cost guide.
When to Stop Plunging and Call
A one-time clog you can usually handle yourself. A pattern is your sign to call. The repeat trips to the hardware store cost more than one proper fix.
Call a plumber when:
- The same drain clogs again within a few weeks
- More than one fixture backs up at once
- You hear gurgling from drains or the toilet
- Water comes up in the basement floor drain
- You smell sewage near a drain
We serve Ajax, Whitby, Oshawa, Pickering, Bowmanville, and the rest of Durham Region, with 24/7 help if a clog turns into a backup after hours through our emergency plumbing team.
Stop fighting the same clog every month. Call us at (647) 560-2817 or request a free estimate and we will find the real cause and clear it for good.
Frequently Asked Questions
Why does my drain keep clogging after I clear it?
Because clearing the surface blockage leaves the cause behind. Grease coating the pipe walls, hair and soap buildup, tree roots, or a sagging pipe will keep catching debris. A plunger or store cleaner only treats the symptom. A proper drain cleaning or camera inspection finds and removes the source.
Are chemical drain cleaners bad for my pipes?
They can be. The harsh chemicals generate heat and can soften or damage older pipes, especially plastic and aging metal lines. They also rarely clear a deep or root-based clog. For a recurring problem, a drain snake or camera inspection is safer and far more effective.
How do I know if the clog is in my main sewer line?
Watch for clogs in more than one fixture at once, gurgling sounds from drains or the toilet, or water backing up in the basement floor drain when you run water upstairs. These point to a blockage in the main line, not a single fixture. That needs a plumber with a snake or camera.
How much does professional drain cleaning cost in Ajax?
Drain snaking starts at about $99, and a typical full drain job runs $250 to $350 depending on the location and severity. A camera inspection may be added for a stubborn or repeat clog. You always get a flat quote before any work begins.
Can tree roots really get into my pipes?
Yes. Roots seek out water and slip into tiny cracks or loose joints in the sewer line, then grow inside and catch passing debris. This is common in older Durham Region homes with clay or aging pipes. A camera inspection confirms it, and we clear the roots and recommend a long-term fix.