Most Common Causes of Clogged Drains

A clogged drain is one of the most common, and most frustrating, plumbing problems homeowners face. Whether it's a slow-draining kitchen sink, a backed-up shower, or a toilet that won't flush properly, drain clogs can disrupt your daily routine and, if left untreated, lead to more serious plumbing issues.

At Mountain Time Plumbing, we clear clogged drains across Treasure Valley every single day. Here are the most common causes of drain clogs we encounter, and practical tips to help you prevent them.

Grease, Fat, and Oil Buildup

The number one cause of kitchen drain clogs is grease. When you pour cooking grease, fat, or oil down the drain, it may be liquid at first, but as it cools, it solidifies and coats the inside of your pipes. Over time, this buildup narrows the pipe opening and traps food particles, creating a stubborn blockage.

Even small amounts of grease can accumulate over weeks and months. The best prevention is simple: never pour grease down the drain. Instead, let it cool and solidify, then dispose of it in the trash. Wipe greasy pans with a paper towel before washing them.

Hair

Hair is the leading cause of bathroom drain clogs, and it's one of the trickiest to deal with. Hair binds with soap scum and other sticky substances to form tough clumps that block water flow. This is most common in shower drains, bathtub drains, and bathroom sinks.

A simple mesh drain cover or hair catcher can dramatically reduce hair clogs. These inexpensive devices sit over or inside the drain and catch hair before it enters the pipe. Clean them regularly for best results.

Soap Scum

Traditional bar soap is made with fats and oils that combine with hard water minerals to form a sticky residue called soap scum. This residue coats the inside of pipes and gradually builds up, reducing water flow and trapping other debris.

In Treasure Valley, where hard water is prevalent, soap scum buildup is an especially common problem. Switching to liquid or synthetic soap products can help reduce soap scum formation. A whole-home water filtration system also makes a big difference by reducing the mineral content that contributes to scum.

Food Waste

Even with a garbage disposal, certain foods should never go down the kitchen drain. Common culprits include:

The best practice is to scrape food waste into the trash or compost bin and use the disposal sparingly for small scraps only.

Tree Root Intrusion

Tree roots are a major cause of sewer line clogs, especially in older Boise-area neighborhoods with mature trees. Roots are naturally drawn to the moisture and nutrients inside sewer pipes. They can enter through tiny cracks or joints in the pipe and, once inside, grow rapidly to create a dense root mass that blocks the line.

Signs of root intrusion include multiple drains backing up simultaneously, gurgling sounds from toilets, and sewage odors in the yard. Root intrusion requires professional intervention, typically starting with a camera inspection to confirm the cause and locate the damage, then sewer line repair or replacement depending on the pipe's condition.

At Mountain Time Plumbing, we use advanced camera inspection technology to diagnose root intrusion and determine the best course of action.

Mineral Buildup from Hard Water

As we mentioned, Treasure Valley has notably hard water. The calcium and magnesium in hard water can precipitate out and form scale deposits inside drain pipes, gradually narrowing the opening and slowing drainage.

This is a slow process that happens over years, but it's one of the reasons older homes in the area are more prone to drain problems. A whole-home water conditioning system can prevent further mineral buildup, and professional drain cleaning can remove existing deposits.

Foreign Objects

It's surprisingly common for objects to end up in drains, especially in homes with young children. Toys, jewelry, cotton swabs, dental floss, feminine hygiene products, and "flushable" wipes are frequent offenders.

Despite what the packaging says, flushable wipes do not break down like toilet paper and are a leading cause of sewer clogs. The only things that should go down a toilet are human waste and toilet paper, nothing else.

How to Prevent Drain Clogs

Prevention is always cheaper and less disruptive than dealing with a clog. Here are our top tips:

When to Call a Professional

While minor clogs can sometimes be resolved with a plunger or drain snake, persistent or recurring clogs usually indicate a deeper problem. If you're experiencing any of the following, it's time to call Mountain Time Plumbing:

We offer professional drain cleaning services using modern equipment that clears blockages without damaging your pipes. We also provide camera inspections to identify the exact cause and location of persistent clogs.

Keep Your Drains Flowing

Don't let a clogged drain turn into a plumbing emergency. Whether you need a quick drain clearing or a comprehensive sewer line inspection, Mountain Time Plumbing is here to help. We serve Boise, Meridian, Eagle, Kuna, Nampa, Caldwell, Star, Garden City, and all of Treasure Valley.

Contact us today to schedule service. Every appointment includes a free estimate and an upfront price before work begins.