There is a strong sewer smell coming from my basement. It started a few days ago and is getting worse.
A sewer smell in the basement is usually caused by a dry P-trap, a cracked or disconnected sewer line, or a failed wax ring on a basement toilet. Start by checking all floor drains in the basement — pour a gallon of water down each one. Floor drains have P-traps that hold water to block sewer gas. If the drain has not been used in months, the water evaporates and sewer gas enters. This is the cause about 60 percent of the time and the fix takes 30 seconds. If the smell persists after filling all traps, check the wax ring seal on any basement toilet — if it has degraded, sewer gas leaks at the base. You may notice water around the toilet base as well. A new wax ring costs 5 dollars and requires removing and resetting the toilet. If neither of these is the cause, you may have a cracked sewer pipe in the wall or underground. A plumber can perform a sewer scope inspection using a camera for 100 to 300 dollars to identify cracks, breaks, or root intrusion in your sewer line.
