What is a house trap?
House traps, also known as sewer traps or p-traps, are U-shaped plumbing pipes that use gravity to retain a small volume of exiting water, which creates a liquid barrier that stops odors or gases from entering the house – or even traveling from a lower section of sewer pipe back up and through a sink or shower drain. Many homeowners, and even other real estate agents, are not familiar with house traps because they are usually located underground and out of sight. It isn’t until a major problem occurs that they are discovered.

This is a rare photo of a house trap installed above ground. You can recognize it from its shape and the chrome cap on top.
For the older homes in Brookside and the surrounding neighborhoods, these types of house traps are a typical occurrence. Newer homes usually do not have house traps because advancements in plumbing have made them obsolete.
Since older homes have house traps that have often been around for decades, when issues occur fixing them can be costly. They can easily become obstructed because of their shape. They are often made of cast iron which is a metal that deteriorates over time making them more prone to buildup and blockage. An obstructed house trap can quickly become an urgent situation – complete with distasteful odors, slow drainage in sinks and toilets, and backflow/flooding in basements.
House Trap Maintenance
Today, plumbers recommend that homeowners with house traps have regular maintenance and cleaning performed to help prevent clogs. Having a professional inspector clean your sewer main line and inspect your house trap on a yearly basis can help prolong its life. You also have a better chance of catching a problem with your house trap before any major issues occur.
Fortunately, there are everyday tactics homeowners can use to protect plumbing and house traps. For instance, never flush anything down the toilet, or pour anything down the drain that is not biodegradable. This includes wipes, sanitary products, and paper towels, which many manufacturers falsely declare are biodegradable. No matter how much a brand touts that their wipes are “biodegradable”, they are not! Flushing these is like flushing a plastic bag down your drain. Even large wads of toilet paper or varieties 3-ply and up can block a house trap. It is also important to avoid putting large chunks of food, or oils, fats, or grease down the drain. Even some types of dish soap can lead to a clog.
For a full inspection of your home’s house trap and overall sewer line, talk with Ellen’s trusted sewer experts, Sewer Doctors. Watch the video at the end of this blog for more information on the importance of sewer line inspections, especially when you are purchasing a home. John also talks about sewer line insurance, something anyone with an older home should have. A problem with your sewer line can land you with a very hefty repair bill when you least expect it! For more information about sewer line insurance, check out Service Line Warranties of America.
Replacing Your House Trap
For those who have a house trap that is regularly causing them problems, plumbers recommend having them replaced with a sewer cleanout. A sewer cleanout is a vertical, capped-off pipe that extends from your existing line. It prevents sewer odors and gases from entering your home and makes correcting any clogs or drainage issues in your sewer line much easier. Sewer cleanouts are also constructed from durable PVC, so you won’t have to worry about it deteriorating like cast iron.
Call Ellen! She’s got a guy!
Inspecting, cleaning, or simply want to learn more about updating drainage with a sewer cleanout? Give Affordable Plumbing and Sewer a call. Their expert plumbers are highly knowledgeable and understand the ins and outs – and curves – of 100+ year-old plumbing.