Why Are Several Drains Backing Up at Once?

What it usually looks like

• Flushing a toilet makes water rise in the shower or tub
• The washing machine drains and a floor drain or toilet overflows
• The lowest fixtures in the house back up first, often a basement or ground-floor shower
• Every drain in the house is slow at the same time
• Water or sewage appears at an outdoor cleanout cap
• Gurgling from several fixtures preceded the backup by days or weeks

Likely causes, most common first

1. Tree roots in the sewer line

   Roots enter at every joint in clay, concrete and old ABS sewer pipe, following the moisture and nutrients inside. They grow into a mat that catches paper and solids until the line closes. In our wet climate with fir, cedar and maple on every lot, roots are the leading cause of main line backups, and they come back on a schedule unless the line is repaired.

2. A grease or sludge blockage in the main drain

   Kitchen grease, soap and sediment coat the main drain over years. A low-slope section or a belly where the pipe has sagged collects it until the pipe is mostly closed. Flushable wipes finish the job.

3. A full or failed septic tank

   On a septic system, when the tank is full of solids or the outlet baffle has broken and plugged the drainfield, nothing leaves the house. Every drain backs up at once, often after a holiday with a full house. No cable fixes this; the tank has to be pumped and inspected.

4. A collapsed, crushed or offset sewer pipe

   Old Orangeburg pipe flattens, cast iron rusts through on the bottom, and a section under a driveway can crush under vehicle weight. Settling in our glacial till soils pulls joints apart. When the pipe itself has failed, cleaning only buys time until the camera shows what has to be dug up.

5. A failed sewage ejector or effluent pump

   Homes where the fixtures sit below the sewer or septic tank rely on a pump. When the pump dies or the float sticks, the basin fills and every fixture tied to it backs up. An alarm usually sounds first.

6. A blockage in the public sewer main

   Occasionally the problem is past your property line. If neighbors are backing up too, the utility's main is involved and the sewer district needs to be called.

Safe things to check yourself first

• Stop using water immediately: no flushing, no showers, no laundry or dishwasher
• Locate the sewer cleanout outside, usually a capped pipe near the foundation on the side facing the street or the septic tank; if it is full of water, the clog is downstream of the house
• Check whether the problem is only one bathroom group or the whole house
• On septic, look at the tank lids and the drainfield for standing water or odor
• Ask a neighbor if they are having the same problem
• Move rugs, towels and anything of value away from the lowest drain in the house

How we diagnose and fix it

• Confirm it is the main line by checking the cleanout and the lowest fixture, then shut down fixture use while we work
• Cable the main line from the cleanout with a sectional or drum machine and a root-cutting head sized to the pipe
• Hydro jet the line when grease, sludge or a heavy root mat is involved, using our own jetting truck
• Run the sewer camera after clearing to show you the cause and the condition of the pipe, with footage you can keep
• Install an exterior cleanout if the house does not have one so this never requires pulling a toilet again
• Quote sewer repair or replacement when the camera shows a broken pipe, and refer you to a septic company if the tank is the cause

Questions people ask