P-traps are generally better and are the preferred, code-compliant standard for almost all modern toilets. They are significantly more reliable at maintaining a water seal, which prevents dangerous sewer gases from entering your bathroom.
Choosing between an S trap and a P trap toilet depends entirely on your bathroom's existing outlet. If the drainage is on the floor, go for an S trap. If it's on the wall, a P trap will work best. Picking the wrong trap for the outlet can lead to fitting issues and costly adjustments.
S-traps are banned by modern plumbing codes because their shape causes a self-siphoning effect. When a large volume of water drains, it creates a vacuum that pulls the water out of the trap. This destroys the water seal, allowing noxious and potentially dangerous sewer gases to freely enter the home.
P-traps are known for their reliability and efficiency in maintaining a water seal, which helps to prevent sewer gases from entering buildings. Additionally, P-traps are less prone to syphoning and drainage issues compared to S-traps, making them a preferred choice for both residential and commercial plumbing systems.
No, S-traps are no longer popular or code-compliant. They were phased out decades ago because the S-shape creates a siphoning effect that sucks water out of the trap, leaving your home unprotected from foul-smelling and potentially harmful sewer gases.
PMRs for malignancies of the stomach, kidney, brain, and lymphopoietic system were also elevated, especially among plumbers. Chronic rheumatic heart disease, emphysema, liver cirrhosis, and all external causes of death were the major non-cancer causes with significantly elevated PMRs.
Why are S-traps no longer recommended? S-traps are more likely to siphon out the water seal, making them unreliable. This can lead to sewer gases entering the home, which is why modern codes discourage or prohibit them.
Yes, S-traps are strictly prohibited by modern building and plumbing codes across North America. They are considered an illegal installation for most sinks and fixtures because the S-shape is prone to self-siphoning—the draining water creates a vacuum that pulls the water seal out of the trap. Without that water seal, dangerous and foul-smelling sewer gases can enter your home.
Eliminates siphoning risks: S-traps are more susceptible to having their water seals siphoned away by the flow of draining water. This can lead to the aforementioned sewer gases entering the home. P-traps, with their effective ventilation integration, mitigate this risk substantially.
Change your P-Trap toilet to an S-Trap with our easy to install Standard Toilet Converter. This convenient S-Trap converter comes with rubber/silicone seal for connection to the pipe join. It can be cut to size to fit most applications.
Plumbers advise against chemical drain cleaners because the harsh, corrosive chemicals (like lye or sulfuric acid) generate extreme heat to break down clogs. This reaction can warp plastic pipes, destroy plumbing fixtures, and create a severe safety hazard for professionals if the drain needs to be manually uncloged later.
In plumbing, the "135-degree rule" is a code standard that dictates how much a horizontal drain pipe can bend or change direction. It limits the total cumulative angle of pipe fittings before a system requires an access point (cleanout) or must be vented, ensuring proper flow and preventing chronic clogs.
Many older, traditional plumbers dislike PEX (cross-linked polyethylene) because its speed and ease of use lower the barrier to entry for DIYers, leading to concerns about unshielded materials, water flow restrictions, and chemical leaching. They also cite a lingering trust in the longevity and structural rigidity of copper.
Plumbers consistently recommend Toto as the best overall toilet brand due to its superior engineering, reliable flushing power, and longevity. For high-quality, budget-friendly, or easily serviceable alternatives, they also frequently point to Gerber, American Standard, and Mansfield.
One essential component of any plumbing system is the trap, a U-shaped pipe designed to hold water and block sewer gases from entering your home. Among the various types of plumbing traps, the P-Trap is code-approved, while the S-Trap is strictly prohibited by U.S. plumbing codes.
A clogged toilet trap pipe is the most common reason your toilet won't flush properly. If your toilet bowl fills up but doesn't drain, or drains slowly with a gurgling sound, the trap or drain is likely blocked. Paper buildup, non-flushable items (wipes, hygiene products, etc.), or even mineral scale can restrict flow.
P traps are much, much less likely to become dry than S traps, meaning you're less likely to experience foul odours. A P trap is much more efficient than an S trap when used in the upper levels of a building.
Dawn dish soap can help clear minor, grease-based clogs. Because it is a powerful degreaser, it breaks down fats and oils that often build up in pipes. However, Dawn cannot clear solid blockages like hair, hard water scale, or solid objects.
Yes, water is supposed to sit in the P-trap at all times. This standing water creates a physical seal that blocks noxious and potentially hazardous sewer gases from coming up through your drains and into your home.
Back to "S" traps – The reason "S" traps aren't allowed is because they have the potential to suck, or 'siphon', water out of the trap as the water flows down the drain. On a properly installed "P" trap, there is a vent at the same place the drain turns downwards, which breaks the siphon.
Use a P-trap for all modern sinks, showers, and tubs with wall-mounted drain lines. Avoid using an S-trap in new installations, as its lack of venting causes a siphoning effect that pulls water out of the trap, allowing harmful sewer gases into your home.
Never put anything down your drains or toilets except the "three Ps" (pee, poop, and toilet paper). Other items act as magnets for debris and build up into severe blockages over time, which can require Emergency Plumber Services or result in thousands of dollars in property damage.
Plumbers often dislike push-fit fittings (such as SharkBite) because they are highly vulnerable to improper DIY installation, rely on degradable rubber O-rings, and cost significantly more per fitting than traditional soldered or crimped alternatives.
Yes, S-traps are strictly illegal under all modern U.S. plumbing codes (including the International Residential Code and the Uniform Plumbing Code). Because of their design, they lack the venting necessary to stop a vacuum effect from occurring, which can siphon the water out of the trap and allow dangerous sewer gases into your home.
Yes, sewage pumps and grinder pumps are specifically designed to handle human waste and standard, dissolvable toilet paper. However, they cannot handle excessive amounts of thick paper, "flushable" wipes, or non-biodegradable hygiene products.