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Does A Shower Drain Need A Trap

Shower drains are a widespread problem for homeowners remodeling showers in their bathrooms. Contrary to what you may have heard, there is a simple solution to the common question of whether a drain needs a trap. A U-shaped portion of the drain pipe known as a shower drain trap prevents sewer gases from rising into your bathroom. It is also known as a shower P-trap, shower U-trap, shower S-trap, shower pee trap, or simply the shower trap.

You will notice the effects of their failure right away because these traps are a crucial component of your home’s plumbing system. For example, all showers need a drain trap, which is only necessary because foul odors are the first sign that something is wrong. P-traps are a legal requirement for all shower drains. Every home appliance that connects to the primary plumbing system must meet this requirement to prevent sewer gases and animals from entering the house through drain pipes.

Primarily, these curved pipes are used in shower drains, bathroom sinks, and toilets. It might be hidden under the floor, so you might not notice it, but all bathrooms are required by the requirement to have it. Your family is in danger if your bathroom is lacking or clogged. (Learn How To Remove Silicone Caulk From Fiberglass Shower Stall)

Shower Drain Trap

Does A Shower Drain Need A Trap?

The U.S. and many other countries require a P-trap for shower drains. The shower pee trap keeps unpleasant gases out of the shower. Its shape and design prevent animals and other items from entering the home.

Methane and hydrogen sulfide is flammable sewer gases. Other gases like carbon monoxide reduce oxygen in the home and are poisonous, causing suffocation. Every shower needs its own P-trap to work, and even adjacent bathrooms can’t share shower P-traps.

How does my shower drain trap work?

The shower drain line P-trap is essential and prevents gases and objects from coming back up while allowing them to flow down the drain when it is working correctly.

Anatomy of shower traps:

Shower Drain Trap Anatomy


Your P-inlet traps is where water enters the trap. For instance, when you shower, all the water enters the P-trap through the drain hole in the bathroom floor and connects to the shower drain plumbing system.

Downward Bent:

The P-downward trap’s bend takes on a “U” or “P” shape. These plumbing fixtures hold the right amount of water to create an airtight seal between the fixtures connected and the P-inlet trap’s sewer sides.

Water flows down the drain when it enters the P-trap for the shower drain; it replaces the water there while maintaining the water seal once it stops. The “trap” part of the name refers to the fact that when sewer gases rise from the outlet side of the P-trap, they won’t pass through the water and into your home.

It traps gases and animals that cannot pass through the water and bend to get to your home. To drain the water in the P-trap during maintenance or to keep the p=trap clean, the downward bent has a clean out in the center of the ‘U’ section of the trap. (Learn How To Fill Gaps Between Baseboard And Floor)


P-shower water exits the trap and goes into the sewer line to the main sewer. The shape determines the name of a shower drain trap.

The P-trap is P-shaped, while S-traps have an ‘S’ shape on a vertical plane where water flows downwards rather than sideways. All drain traps work the same way as described.

However, it can get confusing which to use, so call a professional plumber, and ensure your home is up to code.

Shower Drain P-Trap Depth

P-trap water exits the trap and goes into the sewer line to the main sewer. The shape determines the name of a shower drain trap. The P-trap is P-shaped. S-traps have an ‘S’ shape on a vertical plane where water flows downwards rather than sideways. All drain traps work the same way as described above.

How far can my P-trap be from my shower drain?

The shower drain and P-trap are 5 feet apart. Therefore, P-trap should be close to the shower drain inlet. For the best results, place the P-trap under the shower drain.

With P-traps, the further they are from the shower drain, the more smells can enter the home. The smell of decaying dirt between the drain and P-trap may not be from the building’s main plumbing system.

Dimensions of Shower P Trap

The minimum size of a shower drain P-trap is 2 inches, the trap’s pipe diameter. This differs from drain traps for the bathroom and kitchen sink (114 inches) and the kitchen sink (112 inches).

Looking at a shower trap diagram from the side, the trap size is the thickness of the pipe that curves to make the P-trap.

How To Clean A Shower P-Trap

If you have a clogged drain, you’ll need to clean it to make your shower drain work as it should when pouring water down the drain so it can make its way to the septic tank.

Here are a couple of ways to keep your drains clean.

Method 1 Removing Your P-Trap

  1. Remove the flooring above the shower drain opening and the P-trap after you have found its location on the shower floor.
  2. Place a bucket underneath it to prevent spills and then unplug it from the outlet pipe.
  3. Remove any nuts and screws on the trap arm to release the P-trap.
  4. After 15 minutes, soak it in white vinegar and baking soda solution, brush it, and then rinse it with warm water.
  5. Connect to the outlet and then replace the floor covering and drain cover.

Method 2 Not Removing Your P-Trap

  1. Add a cup of white vinegar to the shower drain after adding half a cup of baking soda.
  2. After covering the shower drain for 15 minutes, run hot water through it.
  3. It would be best if you also used a drain cleaner or a plumber’s snake as you flush it with clean water to clean the shower drain.
  4. Avoid using harsh drain cleaners that could harm your bathroom’s plumbing. Instead, choose enzyme-based drain cleaners, which slowly consume the debris without damaging your pipes.
  5. To keep your shower stall working properly, follow these cleaning instructions regularly.

P-Trap Alternatives

Building codes and the accessibility of other types of drain traps are two issues that arise when homeowners wonder whether a shower drain requires a P-trap installation.

People then look for P-trap substitutes like a bell, bottle, and drum traps. But unfortunately, Bell traps are no longer used.

Building regulations differ, so what is permitted in one state may differ from another.

Check the building codes in your area before considering using one of the more well-liked P-trap for shower drain alternatives because some codes vary from state to state. (Learn How Long Does It Take For Tile To Set)

As we previously mentioned, there are various plumbing codes, and if you’ve lived or traveled abroad, you may be familiar with the Bottle Trap. Bottle traps are a distinctive P-trap substitute used for years in Europe.

A bottle trap has the same function as a P-trap because it is made to stop bugs and sewer gasses from returning to the bathroom. However, it is not what you install beneath a bathtub or shower. Instead, bottle traps are used in the pipes under a sink, which may be against local building codes.

A shallow P-trap is more typical and ideal when there is not enough room for a tub or shower drain. However, they may still violate the law even with a connector and plug.

You may also come across the Hepvo waterless valve, which is only appropriate for recreational vehicles. In a shower, only employ a trap explicitly made for them. You risk breaking the law if you try to use a bottle trap or anything made for foreign fixtures in the United States.

P-trap vs S-trap Shower Drains


Is a P-trap Better Than an S-trap in Shower Drains?

Before P-traps, S-traps took up a lot of room. Newer traps aren’t used under showers or tubs.

Should You Have Standing Water in a Shower Drain?

If the P-trap is shallow, it’s not unusual to look down and see some standing water there. However, just because you can’t see any water doesn’t mean the P-trap is dry.

Can You Use a Grease Trap With a Shower Drain?

No, and you can be sure that it violates most local building codes. A grease trap is not a good substitute for a P-trap; it is for catching grease.

Does a Shower Drain Need a P-Trap?

Water will drain fine without a P-trap in a shower drain. P-traps create a barrier between your bathroom and the sewer system.

Some building code requirements state a P-trap or another trap, such as a J-trap or U-trap, is used to combat sanitation and health concerns. (Learn How To Remove Glue From Hardwood Floor Installation)

What Happens With No P-Trap in My Shower Drain?

  1. Odors: Without a P-trap, you’ll notice sewage odors. These odors have been compared to feces and rotting fish. Without a P-trap, you never know what sewer smell could enter your bathroom.
  2. Code Enforcement Issues: In some countries and states, there is no direct building regulation requiring a P-trap. Check local regulations before building or renovating your bathroom to avoid fines or redoing your work.
  3. Serious Health Problems: P-traps block foul odors and sewage gas from decomposing sewer material. Sewage gas can cause short-term nausea. Long-term exposure can cause seizures, smell loss, pink eye, coma, or even death.
  4. Insects: Bathroom odors and sewage gas attract insects. Sewage attracts flies and cockroaches, and mosquitoes love moist bathrooms.

What are the parts of a P-trap?

  • Inlet: The shower drain P-trap is a straight pipe that carries wastewater to the P-trap.
  • The Downward bent pipe: The U-shaped pipe creates a sealed wastewater collector to stop odors in the shower drain pipe.
  • Outlet: The outlet presents a horizontal structure. Like a pipe that balances the air pressure, it effectively guides wastewater and sewer gas to leave the shower drain trap vent pipes.

Does A Shower Drain Need A Trap