Your Main Sewer Line Is Working Hard. Here’s How to Keep It That Way.

There’s a pipe running from your house to the city sewer (or your septic tank) that handles every drop of water and waste that leaves every drain, toilet, and appliance in your home. It works around the clock, completely out of sight, and most homeowners never think about it until something goes very wrong. 

Bell Plumbing, Heating, Cooling & Electrical has been handling Denver sewer and drain issues since 1926, and the calls that are hardest to get to quickly are the ones that could have been prevented. Here’s what our Denver plumbers think you should know about mainline maintenance before you’re dealing with an emergency.

What Is the Main Sewer Line?

Your home has two types of drain lines:

• Branch lines carry waste from individual fixtures, like a toilet, a sink, or a shower, and connect to the main line.
• The main line (sometimes called the mainline or main sewer line) is the single large pipe that collects all of it and carries it out of your home entirely.

Because everything flows through it, any blockage in the main line affects every drain in the house at the same time. That’s what makes a mainline backup so disruptive. It’s not just one slow sink. It’s all of them.

What Causes Mainline Buildup?

A few things accumulate in sewer lines over time:

• Grease and soap scum. Even if you’re careful about what goes down the drain, some grease and soap residue makes it into the line. Over time, these deposits cling to pipe walls and narrow the passage.
• Tree roots. This is one of the most common sewer line problems in Denver and across the Front Range. Roots are naturally drawn toward the warmth and moisture of sewer lines. They work their way into joints and cracks, and over years can create serious obstructions or cause pipes to break entirely.
• Debris and scale. In older homes, mineral buildup and pipe scale can narrow the interior of the line. Combined with any other debris, this creates conditions where clogs develop faster and more frequently.

How Often Should You Have the Mainline Cleaned?

For most homes, a mainline cleaning every 18 to 24 months is a reasonable starting point. That said, a few factors can shift that schedule:

• Older homes with original cast iron or clay pipes often need more frequent attention
• Homes with mature trees nearby, especially cottonwoods or willows (common in Colorado), benefit from annual cleanings
• If you’ve had recurring slow drains or backups, more frequent maintenance is worth it

Your plumber can help you figure out the right schedule after inspecting the line.

What Does a Mainline Cleaning Involve?

Drain snaking is the most common method. A motorized auger runs through the line to break up and clear blockages. It’s effective for most routine cleaning and for addressing clogs.

For lines with heavier buildup, grease accumulation, or root intrusion, hydro jetting is more thorough. A hydro jetting machine sends a high-pressure stream of water through the pipe, scouring the walls clean and flushing debris out completely.

Before either method, a camera inspection gives the plumber a real-time look at the condition of your line, identifying any cracks, root intrusion, or areas of concern before they become bigger problems.

Warning Signs to Watch For

Early indicators of mainline trouble include:

• Multiple drains in the house running slowly at the same time
• Gurgling sounds from toilets or drains after using other fixtures
• Water backing up in a floor drain, bathtub, or shower when you flush the toilet
• Sewage odors coming from drains

If you’re noticing any of these in your Denver home, it’s worth getting the line looked at sooner rather than later. A backup that starts small can escalate quickly, and sewage backing up into your home is both a health hazard and an expensive mess to clean up.

Is Preventive Cleaning Worth the Cost?

Almost always, yes. A routine cleaning is a fraction of the cost of clearing a serious backup, replacing a collapsed pipe, or repairing water damage inside the home. Most homeowners who’ve dealt with a mainline emergency say the same thing afterward: they wish they’d been more proactive.

Don’t Wait for a Backup

Bell offers drain cleaning services in Denver and across the metro area, with same-day availability for urgent situations. If it’s been a while since your mainline was inspected (or if you’ve never had it done), schedule a service call and get ahead of it.

Call (303) 731-5469