A slow drain is your plumbing’s way of giving you a heads up. The water still goes down, just not as fast as it used to, and it is easy to ignore until the day it stops completely. The good news is that a slow drain is usually the cheapest time to fix the problem.
Here are the most common reasons drains slow down, what you can safely try yourself, and when it is time to call a plumber.
A slow drain is usually hair, grease, or buildup, and a plunger or drain snake can clear many of them. If several drains are slow, or it keeps coming back, the problem is deeper in the line.
7 Common Causes of a Slow Drain
1. Hair and soap scum
This is the leading cause in bathroom sinks, tubs, and showers. Hair catches on the pipe walls and mixes with soap scum to form a thick, sticky clog that grows a little every day.
2. Grease and food buildup
In the kitchen, cooking grease and oil cool inside the pipe and coat the walls. Food particles stick to that coating, and over time the opening gets narrower and narrower.
3. Foreign objects
Cotton swabs, dental floss, wipes, and small toys all find their way into drains. Even the wipes labeled “flushable” do not break down the way toilet paper does.
4. Mineral buildup
In older homes, mineral scale can build up inside pipes over decades, shrinking the space the water has to flow through.
5. Tree roots in the main line
If you live in an older neighborhood with mature trees, roots can find tiny cracks or joints in your sewer line and grow inside. They are a common cause of slow drains that keep coming back.
6. A blocked vent
Your plumbing needs air to drain properly. A blocked vent pipe on the roof can cause slow draining and gurgling sounds, even when the drain itself is clear.
7. A clog in the main line
If several fixtures in the house are draining slowly at once, the problem is probably not at any one sink. It is likely further down, in the main drain line.
What You Can Try Yourself
- Use a plunger. A good seal and steady pumping clears many minor clogs in sinks and tubs.
- Clean out the hair. A cheap plastic drain snake, the kind with little barbs, pulls out surprising amounts of hair from tub and sink drains.
- Flush with very hot water. For grease, hot tap water can help move things along. Skip boiling water if you have PVC pipes, since it can soften fittings.
- Try baking soda and vinegar. It will not clear a serious clog, but it can freshen a drain and loosen light buildup.
- Add a hair catcher. A simple strainer in the shower and tub stops most hair before it ever reaches the pipe.
A cheap hair catcher is the best drain cleaner there is. Put one in every shower and tub, and most hair clogs never happen.
Why We Skip Chemical Drain Cleaners
It is tempting to grab a bottle of drain cleaner, but we recommend against it. The harsh chemicals can damage older pipes, they are hazardous if they splash on skin or eyes, and they often only punch a small hole through the clog instead of clearing it. They can also sit in the pipe and put the next person who works on it at risk. A mechanical fix, like a snake or hydro jetting, clears the clog without the downside.
When to Call a Plumber for a Slow Drain
It is time to call if:
- More than one fixture is draining slowly
- Toilets gurgle when you run a sink or the washing machine
- You smell sewage coming from a drain
- The clog keeps coming back after you clear it
- Water is backing up into a tub, shower, or floor drain
Recurring clogs usually mean the real problem is deeper in the line. A camera inspection lets us see exactly what is going on instead of guessing.
Slow Drain Help in Boulder County
If you have a slow drain you cannot fix, or one that keeps coming back, we can find the real cause and clear it safely. See our drain cleaning services or call us at (720) 940-3661. We serve Boulder, Longmont, Lafayette, Louisville, Erie, Superior, Niwot, and Gunbarrel. Every technician is licensed with the State of Colorado, and you can verify that through the Colorado Division of Professions and Occupations.