Branch clog vs. main line
One slow tub or sink is a local clog cleared at the fixture. Water backing up in several places, or a floor drain rising when the washer runs, points to the main drain to the street, a bigger job.
A drain that backs up twice in a year is usually a sewer‑line problem
One backup is an event. A second backup in the same line within a year is a pattern, and patterns live in the main sewer line between the house and the street, not in the fixture you noticed. In older Greater Boston neighborhoods that line is often clay tile or early cast iron, and both fail in ways cabling only treats temporarily.
Clay pipe joins in short sections, and tree roots find every joint; you can cut them out, but they grow back on their own schedule. Cast iron rusts and scales from the inside until the channel narrows and catches waste. A length of pipe that has sunk creates a low spot that never fully drains. The camera footage is what tells us whether a spot repair, a trenchless liner, or a dig is the right call, and we walk you through what the screen shows before any of that is scheduled.
