Why Your Drains Are Slow (And What To Do About It)

A slow drain is one of those problems that starts as an annoyance and ends as an emergency. The good news? Most slow drains have a clear cause, and knowing what to look for can save you from a much bigger bill down the road.

The Most Common Causes of Slow Drains

1. Hair and Soap Scum Buildup

This is the number one culprit in bathroom sinks and showers. Hair wraps around the drain stopper and traps soap scum, creating a dense mat that water struggles to pass through. Over time, this buildup hardens and becomes nearly impossible to clear with a plunger alone.

What you can do: A simple drain snake or zip-it tool can pull out hair clogs near the surface. For deeper buildup, a enzymatic drain cleaner used monthly can help break down organic material before it becomes a problem.

2. Grease and Food Debris in Kitchen Drains

Cooking grease may go down the drain as a liquid, but it solidifies inside your pipes, coating the walls and trapping food particles. This is especially common in Ontario homes with older cast iron or galvanized steel pipes, where the rough interior surface gives grease even more to cling to.

What you can do: Never pour grease down the drain. Use a grease container, and run hot water with dish soap after every meal prep. If you already have a grease clog, boiling water and baking soda can help soften it, but professional hydro-jetting is often the only real solution.

3. Mineral Buildup from Hard Water

Southwestern Ontario has moderately hard water, which means calcium and magnesium deposits slowly accumulate inside pipes. Over years, this can narrow the pipe diameter significantly, reducing flow even when there is no actual clog.

What you can do: A water softener is the best long-term solution. For existing buildup, professional descaling or pipe replacement may be necessary in severe cases.

4. Tree Root Intrusion

This is the serious one. Tree roots naturally seek out moisture, and a tiny crack in your sewer line is an open invitation. Roots grow into the pipe, creating a dense web that catches debris and eventually blocks the line completely. In older Ontario neighborhoods with mature trees, this is more common than most homeowners realize.

Signs it might be roots: Multiple drains are slow at once, you hear gurgling from toilets when running water elsewhere, or you notice sewage odors in the yard. This is not a DIY fix — you need a professional with a sewer camera.

When to Call a Professional

Here is the honest truth: store-bought drain cleaners are harsh chemicals that can damage your pipes and rarely solve the underlying problem. If you have tried a plunger and a drain snake and the problem keeps coming back, it is time to call a plumber.

A licensed plumber can run a camera inspection to see exactly what is happening inside your pipes. In St. Thomas, London, and across Southwestern Ontario, Jumbo Plumbing uses professional-grade camera equipment to diagnose drain issues with precision — no guessing, no unnecessary digging.

Prevention Is Cheaper Than Repair

The best way to deal with slow drains is to prevent them. Drain screens in every sink and shower catch hair and debris before they enter your pipes. Monthly enzymatic treatments keep organic buildup from hardening. And an annual professional drain cleaning — included in Jumbo Protection Plans — keeps your entire system clear year-round.

A single emergency drain cleaning call can easily exceed the cost of a full year of preventative maintenance. If you are dealing with recurring slow drains, a protection plan might be the smartest investment you make for your home.