Partial clog worsens over time

Quick Answer:

A slow drain that gets steadily worse over days or weeks usually means a partial restriction in the main sewer or a shared branch. Track which fixtures are affected, open the main cleanout and try snaking the line to test whether the restriction is removable. If snaking gives only short relief, schedule a camera inspection to look for roots, a sagging pipe (“belly”), or collapsed sections, then get quotes for root cutting, relining, or full replacement based on what the camera shows. For more background on gradual backup patterns, see Partial clog causes random backups.

Why This Happens

Partial restrictions let some water through but slow flow, so everyday use gradually reveals the problem. Common causes:

• Tree roots infiltrating joints and narrowing the pipe
• Grease, hair, and solids building up until flow is compromised
• Pipe sagging (a belly) that traps solids and slows flow
• Broken or collapsed sections reducing the clear diameter

When the main is affected you’ll often see multiple fixtures slow at the same time — sinks and showers may drain more slowly, toilets may take longer to empty, and the washing machine or bathtub may back up first. If several fixtures slow together, it’s likely the Main sewer line partially clogged.

Step-by-Step What to Do

1. Document how the slowdown progresses

• Keep a short log over several days: date, time, which fixture(s) are slow, whether water backs up or just drains slowly, and any sewage smells.
• Note triggers: after a shower, after dishwasher use, or after heavy laundry loads. This helps point to a partial, progressive restriction rather than a single clog.
• Photograph or note any visible backups or standing water in fixtures.

2. Open the cleanout and test with a snake

• Locate the main cleanout (usually a capped pipe near the house or in the basement). Remove the cap carefully—have a rag and a bucket handy for drips.
• Run a drain snake or auger from the cleanout into the main sewer. For a true main restriction use a power or sectional snake rated for mains, or hire a plumber to operate it.
• Note what you pull back (roots, grease, solids). If the snake clears and flow returns, monitor how long the relief lasts.

3. If snaking gives only short relief, get a camera inspection

• A video camera run through the pipe will show roots, bellies, misaligned joints, or collapsed sections. Ask the inspector to record the run and mark the problem location.
• Camera findings guide the repair choice: mechanical root cutting or hydrojetting for roots/grease, relining for cracks and separations, and replacement for severe collapse or bellies.

4. Obtain and compare quotes

• Get at least two written quotes that reference the camera report and list specific repairs: root cutting/hydrojetting, cured-in-place pipe (CIPP) relining, or full dig-and-replace.
• Compare scope, warranties, timeline, and cleanup. Ask whether the quote includes permits and restoration of landscaping or hardscaping.
• Keep records and the camera video; it helps when reviewing estimates and guarantees.

What Not to Do

• Avoid repeatedly dumping chemical drain cleaners into the system. They rarely fix main-line issues and can damage pipes while delaying proper diagnosis.
• Do not rely on temporary fixes (short snaking sessions or spot repairs) if the slowdown returns or worsens over weeks; these only postpone the real repair.
• Don’t ignore sewage smells or intermittent backups. If the problem worsens over weeks, you detect sewage odors, or multiple snaking attempts give only brief relief, call a professional promptly.

When to Call a Professional

• The slowdown keeps getting worse over several days or weeks.
• You smell sewage in or around the house, or see standing sewage in fixtures.
• Multiple snaking attempts give only temporary relief.
• You find evidence of roots or structural damage, or the camera inspection identifies a belly or collapse.
• If you’re uncomfortable opening the cleanout or using a main-line auger—this is work best left to a pro.

Safety Notes

• Wear gloves and eye protection when opening a cleanout or handling a snake. Sewage can contain harmful bacteria.
• Never mix chemical cleaners; if drain chemicals have been used, warn the professional so they can take proper precautions.
• Power snakes and hydrojetters are dangerous if used incorrectly. Leave powered cutting or pressurized cleaning to trained technicians.
• Do not enter confined spaces (sewer pits) yourself. Leave confined-space work to professionals with proper equipment.

Common Homeowner Questions

• How long can I wait before acting?
  If the slowdown progresses over more than a few days or you smell sewage, act now—delays often make repairs more expensive.
• Will cutting roots fix it permanently?
  Root cutting restores flow but roots typically regrow; camera inspection and long-term fixes (relining or replacement) may be needed.
• Is relining a reliable option?
  Relining (CIPP) is a durable, less disruptive repair for cracks and joint separations but depends on the pipe’s current shape and the camera findings.

More in this topic

For more related fixes and similar symptoms, see Main Line Partial Clogs.