A common plumbing defect found in many older houses is an "S" trap. An "S" trap is named so because it looks like an "S" on its side - it basically consists of a normal trap, and then another trap installed right up against it in an upside-down fashion, as shown below. When water sits in the trap, sewer gases stay out.5 Jun 2012
What is wrong with S-trap plumbing?
But why is the S trap illegal? The “S” trap is prohibited under the Uniform Plumbing Code throughout the United States. This is because the “S” trap will siphon or suck water out from the trap which will end up releasing methane (sewer) gases into the home.14 Aug 2020
What is difference between P-trap and S-trap?
With an S-trap, the drainpipe drops down from the sink and into a conventional trap. It then loops over and exits downward. In a P-trap configuration, the drain also comes down from the sink and into the trap, but instead of looping over and back down, the drain enters a horizontal run before exiting downward.
Is a vented S-trap OK?
The plumbing code requires each fixture in your house to have a trap and each trap to be individually vented. You can't vent an S-trap in this way because it drops immediately to the drain. If you run water through an unvented S-trap, the vacuum created in the pipe can pull water out of the trap, rendering it useless.
Which is better P-trap or S-trap?
P trap vs S trap, which one drains better? P-traps are newer and so have a design advantage. P-traps are suitable for installation on top floors whereas s-traps are suitable for ground floors. P-traps are consistent in maintaining water traps while s-traps have a tendency to dry out.14 Aug 2021
Why would you use an S-trap?
The mechanical purpose of the trap is to hold water to prevent sewer gases containing viruses and bacteria from entering the home through the drain. With an “S” trap drain, the trap is easily siphoned dry with each use and the water seal no longer exists. A properly installed “P” trap will always maintain a water seal.15 Oct 2011
Why does my S-trap keep leaking?
Plastic-pipe traps are more likely to leak when the pipes or washers become misaligned, so check for alignment. Check the pipes for rust or corrosion. If s pipe is corroded or cracked, take it with you to the hardware store to buy an appropriate replacement.12 Sept 2020
Why is an S-trap illegal?
The “S” trap is prohibited under the Uniform Plumbing Code throughout the United States. This is because the “S” trap will siphon or suck water out from the trap which will end up releasing methane (sewer) gases into the home. So, it is a code violation and if you are doing remodeling, you will have to replace it.14 Aug 2020
Can I use S-trap for sink?
An “S” shaped drain was installed (under a sink or tub) which typically diverted slightly and went down into a drain line under the floor. Depending on specific applications, an s-trap drain configuration can work just fine. An air gap is left, allowing gases to escape through the trap.25 May 2020
Why do they still sell S-traps?
You can still buy S-traps in stores, because they have some legitimate uses, but they aren't suitable for beneath your sink. If you currently have an S-trap, it may have been installed before the building codes outlawed them.12 Oct 2020
Can you convert S-trap to P trap?
There are a number of ways to convert an S trap to a P trap. You can use a full conversion kit to change it without any hassle. Otherwise, you have to cut the S trap, put the air admittance valve to convert it to a P trap!21 Aug 2021