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No P-Trap in Shower: A Hygienic Shower P-Trap Alternative

P-traps are a bend in your plumbing that resembles the letter P. You can find these traps just below your sink or shower drain.

P-traps have an essential job. Your plumbing empties out into the sewer. It is the P-trap that blocks the smell of sewage gas from entering your home.

But is a P-trap the only solution? What happens if you decide to go without one? And are there any viable alternatives? This article will answer these questions and also includes which P-trap alternatives you should avoid.

shower drain p-trap
Source: WINNI

Does a Shower Drain Need a P-Trap?

Mechanically, a shower drain does not need a P-trap to function, and water will drain just fine without it. But P-traps have become an essential convenience that creates a barrier between your bathroom and the sewer system.

This essential convenience has even become mandatory in some areas through building code requirements stating that a P-trap or another trap such as a J-trap or U-trap is necessary to combat sanitation and health concerns.

What Happens if There Is No P-Trap in My Shower Drain?

Terrible Odors

If you lack a P-trap, one of the first things you will notice is the terrible odors coming from the sewage system. These odors have been described as fecal matter, rotting fish, and everything in between. You never know what kind of disgusting sewer smell could penetrate your bathroom without a P-trap to protect you.

Issues With Code Enforcement

In some countries and states, there is no direct building regulation that states you need a P-trap. But that’s not always the case, so it’s best to check your local regulations before you build or renovate your bathroom to avoid any possible fines or having to re-do your work.

Health Concerns

P-traps do not only block foul odors but sewage gas which is created from all the decomposing material found in the sewer. Short-term exposure to sewage gas can make you feel sick to your stomach. But being exposed to this gas for a long period can cause seizures, a loss of smell, pink eye, coma, or even death.


The sewage gas and odors emanating from your bathroom can attract insects. Flies and cockroaches will be attracted by the sewage, and mosquitoes will enjoy the moist conditions found in your bathroom.

Shower P-Trap Alternative

The Waterless Trap

There are many P-trap alternatives that claim to work great. But here at Loo Academy, we believe the only alternative that is effective at blocking sewage gas is the waterless trap.

A P-trap works by trapping some of your freshwater in a bend in your plumbing which acts like a barrier that keeps the sewage gas out of your bathroom.

Waterless traps use a flexible self-sealing membrane to block out sewage gas. This membrane opens to allow water to pass through and drain out of your system. But once the water stops passing through your drain, the membrane closes to prevent any sewage gas from entering your bathroom.

Though a waterless trap might cost you more than a standard P-trap, the waterless trap can be much more effective as it does not need any water, which can evaporate over time.

Avoid These Shower P-Trap Alternatives

Bottle Trap

There has been an ongoing debate between contractors and plumbers concerning whether the bottle trap is as good as the P-trap.

The bottle trap may work in some situations, but the main issue with these traps is that they are more prone to clogging. Any clogged drain can create a plethora of new issues.

Another reason we always recommend a P-trap or waterless trap over a bottle trap is that code regulations in some areas prohibit bottle traps.

Grease Trap

You should never use a grease trap in the bathroom. Grease traps were created for kitchens to catch things like lard, cooking grease, and fat before they enter your plumbing system.

While grease traps are great for the kitchen, they will not help at all when it comes to blocking sewage gas from entering your bathroom.


TrapGuard is a product that was developed as an alternative to trap primers. Trap primers work by releasing some water into your trap to keep the trap’s water barrier from evaporating.

Your shower would have to go for weeks-months without use for the water in your trap to evaporate. So in most cases, TrapGuard and trap primers are unnecessary.

You can use a TrapGuard to keep your P-trap moisturized when away on vacation, but a TrapGuard is more of an accessory for your P-trap, and by no means should it be used as a replacement or alternative.

Kyle Tucker

Kyle from Kyle Tucker Plumbing is a certified plumber with over 20 years of professional experience installing plumbing fixtures such as bathtubs, sinks, and toilets, as well as installing gas lines and water pipes, performing bathroom repairs, and more.

Kyle knows how to deal with every plumbing issue that modern homeowners encounter, and he shares his lifelong experience with readers in an engaging and easy-to-digest way.

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At Loo Academy, our mission is to offer trusted advice for everything related to bathrooms (design ideas, plumbing advice, showering & bathing tips, remodeling guides, and more) — a place where we all spend a great deal of time.

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