What causes clogs in New York City apartments and houses?
Most clogs come from a short list of causes, but the buildings here add a few of their own.
Kitchen grease and food
In many apartment buildings, kitchens in a vertical line share one stack. Grease poured down one sink can build up lower in the pipe and affect the units below.
Wipes, hair and paper
Flushable wipes are rarely flushable. Hair and soap form a stubborn plug in tub and shower drains.
Old pipe
Cast iron develops rough scale inside over decades, which catches debris and narrows the pipe. Sagging sections can hold standing water.
Roots and old sewer lines
In houses in the outer boroughs, older clay sewer lines can be entered by tree roots at the joints. If backups keep returning, read about sewer line repair, because cleaning alone may only buy time.

