7 Common Causes of Clogged Drains (and How to Solve Them)

A slow drain is annoying. A completely clogged one? That’s a full-blown emergency. If you’re dealing with standing water in your sink or a toilet that won’t flush, you’re not alone. Clogged drains are one of the most common plumbing issues homeowners face in Knoxville and throughout East Tennessee.

At The Plumbing Authority, our Knoxville drain cleaning pros have cleared thousands of drains over the years, and we’ve seen just about everything that can cause a blockage. The good news? Once you understand what’s causing your clogs, you can take steps to prevent them (and know when it’s time to call in the pros).

Let’s walk through the most common culprits behind clogged drains and what you can actually do about them.

1. Hair Buildup

Hair is the silent drain killer. It doesn’t seem like much when a few strands go down the shower drain, but over time, hair combines with soap and creates a stubborn, sticky mass that catches everything else that flows past.

The fix: Use a drain cover or hair catcher in your shower and bathroom sinks. For existing clogs, a drain snake or zip-it tool can pull out the hair buildup. If the clog is deep or keeps coming back, professional drain clearing can clear it completely and restore proper flow.

2. Soap Scum and Residue

Traditional bar soaps contain fats that combine with minerals in your water to create soap scum. This residue gradually coats your pipes and narrows the opening, slowing drainage over time. Hard water makes this problem worse.

The fix: Switch to soap-free washes when possible. For existing buildup, hot water can help dissolve some of it, but for pipes that are significantly narrowed, hydro jetting uses high-pressure water to completely clear away years of accumulated residue.

3. Food Waste and Grease

Your garbage disposal can handle a lot, but not everything. Coffee grounds, eggshells, pasta, rice, and fibrous vegetables can build up in your pipes. Grease is one of the worst offenders. Liquid grease goes down easy, but it solidifies as it cools and coats your pipes like plaque in an artery.

The fix: Scrape plates into the trash before rinsing. Never pour grease down the drain. Let it solidify in a container and throw it away. Run cold water when using your disposal to help carry waste through. If you’ve already got a grease clog, you’ll likely need professional help to clear it properly.

4. Foreign Objects

Kids dropping toys down the toilet. “Flushable” wipes that absolutely aren’t flushable. Cotton swabs, dental floss, feminine hygiene products. If it’s not toilet paper or human waste, it doesn’t belong in your drains.

The fix: Keep bathroom trash cans accessible so people actually use them. Teach kids what can and can’t go down the toilet. If something does go down that shouldn’t have, don’t keep flushing. You’ll just push it deeper. Call for toilet repair before a simple fix turns into a bigger problem.

5. Mineral Buildup

East Tennessee has hard water in many areas, which means high mineral content. Over time, calcium and magnesium deposits build up inside your pipes, gradually restricting water flow. You might notice this as progressively slower drains or reduced water pressure.

The fix: A water softener can prevent future buildup. For pipes already affected, professional cleaning methods can remove existing deposits and restore full flow.

6. Tree Roots

This one surprises people, but tree roots are drawn to the moisture in your sewer lines. They can infiltrate even small cracks in your pipes, then grow and expand inside them, causing major blockages. If multiple drains in your home are backing up at once, tree roots might be the culprit.

The fix: This isn’t a DIY job. Tree root removal requires professional equipment and expertise. If roots have damaged your pipes, you may need repairs beyond just clearing the blockage. A camera inspection can show exactly what’s happening in your drains and sewers.

7. Pipe Problems

Sometimes the issue isn’t what’s in your pipes. The pipes themselves are the problem. Old cast iron or clay pipes can corrode, crack, or collapse. Pipes installed incorrectly might have low spots where water and debris collect. Bellied pipes (sections that have sunk due to soil settling) create pockets where clogs form easily.

The fix: This requires a professional diagnosis. A video camera inspection can reveal the condition of your pipes and whether you’re dealing with a cleaning issue or a pipe replacement situation.

When to Call for Help

Some clogs you can handle with a plunger or drain snake. But if you’re dealing with recurring clogs, multiple backed-up drains, sewage odors, or water backing up in unusual places, it’s time to call the professionals. These are signs of a more serious problem that needs proper diagnosis and equipment to fix correctly.

The Plumbing Authority serves Knoxville and East Tennessee with straightforward drain cleaning and repair. We’ll figure out what’s actually causing your clogs and fix it right the first time.

Dealing with a drain that won’t clear? Contact us to schedule service. We’re available for emergency plumbing when you need help fast.

Call (865) 245-5251