Typical signs
- Slow drainage, suction noise, bubbling or sewer odour.
- Backup at a nearby fixture or floor drain.
Where it is often found
- Sinks, showers, tubs, washers, floor drains and exterior lines.
What it can mean
- Build-up of grease, soap, hair or wipes.
- Blocked vent, sagging pipe or a blockage farther down the system.
What to check next
- Determine whether one fixture or several are affected.
- Check trap, strainer, accessible vent and usage habits.
Reasonable immediate actions
- Stop heavy use if backup appears.
- Avoid improvised chemical combinations.
When to stop and call a professional
- Backup affecting multiple fixtures, sewer line issues, overflowing toilet or need for powered equipment/camera inspection.
Prevention
- Use strainers, good disposal habits, periodic cleaning and proper slope/venting.