Do Showers Need P-traps? (Shower P-Traps Explained!)

Unlike toilet P-traps, shower P-traps are less popular, with many homeowners not knowing what they are for and whether your shower needs it. This brings us to ask, do showers need P-traps?

Per regulation, every shower needs a P-trap in residential houses or business buildings like gyms. This applies to the United States and many more countries worldwide. However, sometimes, the showers in your building may not have P-traps, so you must find appropriate alternatives.

Knowing your plumbing system’s ins and outs will help you know where to look to make repairs. So, read on to discover more about shower P-traps.

What is the purpose of a shower P-trap?

Do Showers Need P-traps?

Showers require P-traps to prevent sewer gases from entering the bathroom and provide a watertight seal. A P-trap is a plumbing component typically installed beneath your shower drain.

It gets its name because it has a curved shape resembling the letter “P.” The P-trap traps some water in the trap’s curve to create a seal that prevents sewer gases from coming up through the drain and into your bathroom.

Furthermore, the trapped water prevents debris from flowing down your shower drain and causing blockages.

Without a P-trap, you would likely experience unpleasant odors and health hazards associated with sewer gases. In addition, debris would flow into your plumbing system more easily, causing clogs and backups.

Therefore, it is essential to have a P-trap installed in your shower to ensure that your plumbing system is functioning correctly and to protect your health and well-being. The LaSalle Bristol 652010LP Shower Drain/Trap Pack (View on Amazon) is an excellent choice that comes with an ABS P-trap, stainless grid, shower strainer, and poly gaskets for 1.5-inch and 1.25-inch pipes.

Where Is The P-trap In A Shower Drain?

A shower P-trap is installed beneath the shower drain assembly, typically behind an access panel or in a tiny space beneath the floor of your shower. You’ll have to take out the drain grate or cover, then examine the drain opening to find the P-trap.

Alternatively, shine a flashlight into your shower drain to see the P-trap or access it through the access panel or beneath the shower floor.

How Far Can P-trap Be From Shower Drain?

Shower P-traps should be closest to the shower drain. The International Residential Code (IRC) mandates installing traps within 24 inches of the shower drain outlet.

In addition, the IRC requires that the trap arm (the horizontal pipe connecting the P-trap to the drain pipe) be sloped at a minimum of 1/4 inch per foot to ensure proper drainage. Make sure your trap arm isn’t longer than 30, and the drain length from the shower base to the vent does not exceed 6 feet.

Keeping the distance between your shower drain and the P-trap to a minimum ensures the trap effectively prevents sewer gases from going into your bathroom. Additionally, install the P-trap correctly to guarantee its effectiveness in keeping sewer gases out and facilitating proper drainage.

Does P-trap Have To Be Directly Below Shower Drain?

A shower P-trap does not have to be fitted directly below your shower drain, but make sure it is as close to the shower drain as possible.

However, sometimes installing the P-trap directly below the shower drain isn’t possible due to space constraints or other factors. In such cases, a licensed plumber will help determine the best possible location for the P-trap to ensure it effectively prevents sewer gases from entering the bathroom.

How To Install A Shower P-trap

Installing a sink trap is a pretty straightforward task that will take you less than 30 minutes but a shower P-trap is a totally different situation. Since shower P-trap installation entails working with your drainage and plumbing systems, a professional plumber is better suited for the job.

However, you can install your shower P-trap yourself if you have the necessary expertise. Here is how to do so:

  • Remove the existing drain cover or grate from the drain shower.
  • Take out the drain assembly from your shower drain using a drain wrench or pliers.
  • Install the P-trap, ensuring you get the correct orientation which is the trap’s curve facing the drain. Tighten the drain pipe connections using a wrench or pliers.
  • Install the trap arm, making sure it is slopped at least 1/4 inch per foot and not over 30 inches long.
  • Install the new shower drain assembly, ensuring it is securely fastened to your shower floor or subfloor.
  • Run the water to test your new P-trap and shower drain. Check for leaks or drainage issues.

What Happens If Your Shower Doesn’t Have A P-Trap?

As mentioned, some showers may not have a P-trap, which is not good considering their importance. Its absence can cause several problems, including:

a) Foul Odors

Without a P-trap, sewer gases can enter your bathroom and cause unpleasant smells. Nobody wants a foul-smelling bathroom and home in general, so to ensure your bathroom doesn’t smell like a sewer, make sure there’s a shower P-trap.

Shower p-trap low profile

b) Bugs and Rodents Inside Your Home

Typically, bugs and rodents access your home through different entry points, from easy ones like opened doors to unconventional ones like drains. Plumbing systems components like P-traps often help keep unwanted visitors out.

Therefore, without a P-trap, bugs and rodents can find their way into your home, wreaking havoc. This can range from destroying structures to spreading diseases.

c) Drain Blockages

A P-trap helps catch debris and keep them from entering your plumbing system. Without a P-trap, your drain may become clogged with hair, soap scum, and other debris, leading to slow draining or complete blockages.

d) Health Risks

Sewer gases contain harmful substances like methane, carbon dioxide, and hydrogen sulfide, which can cause health problems if inhaled in large quantities. Without a P-trap, these gases will make their way into your home, exposing you to health risks.

Alternatives for A P-trap in The Shower

If you cannot fit a P-trap into your shower drain because of different constraints, you can consider the available alternatives. These are:

1. HepvO Waterless Valve

The RV industry developed the HEPVO waterless valve, an alternative to a traditional P-trap used in certain plumbing systems. It is designed to prevent sewer gases, among other unpleasant odors, from entering your home through the shower drain.

This component creates a seal that prevents the reverse movement of air and water. A HepvO waterless valve is ideal for tight spaces where you cannot fit a traditional P-trap because it is compact.

Moreover, it is a good choice in areas where P-trap installation goes against local building codes. Another upside is easy installation and maintenance.

The HepvO waterless valve is used in various plumbing applications like sinks, showers, and floor drains. It is also ideal for mobile applications such as RVs and boats with limited space.

However, remember a HepvO waterless valve is unsuitable for every plumbing application. Therefore, consult a licensed plumber before installing it to determine if it is the right solution for your specific plumbing needs.

2. Bottle trap

This trap prevents unpleasant odors and sewer gases from entering a building or your home through sink drains in residential and commercial areas. The name bottle trap is because of its shape, which looks like a bottle turned upside down.

A bottle trap features a horizontal inlet pipe that connects to the sink drain and a curved trap section to hold water and prevent sewer gases from entering the space. It also has a vertical outlet pipe that connects to the primary drain line.

They are usually plastic or metal and available in various sizes. The installation of bottle traps is pretty straightforward, and so is their maintenance and replacement should they get worn out or damaged.  

Furthermore, they are cost-effective and reliable when it comes to keeping odors and sewer gases out. Also, they occupy less space than S and P-traps, making them ideal for tiny spaces.

However, while you can use a bottle trap instead of a P-trap, check whether your area’s building codes allow the installation. That’s not all; their biggest drawback is that they are more susceptible to clogs than traditional P-traps since they have a tinier curved section that is more likely to be blocked.

However, regular maintenance and cleaning help prevent clogs and ensure the bottle trap works effectively.

You must identify the right bottle trap and size suitable for your shower drain before installation.

Shower p-trap alternative

What You Shouldn’t Use As An Alternative for Shower P-trap

a. Grease Trap

This trap was designed to capture and prevent grease, oil, and other fats from entering the main sewer system. It is commonly used in commercial kitchens and other food service establishments to prevent clogs and backups in the plumbing system.

They intercept wastewater and allow it to cool, which causes the fats and oils to solidify and float to the surface. The solidified fats and oils are then trapped in the grease trap, while the remaining wastewater is allowed to flow into the sewer system.

Grease traps are typically installed underground or on the kitchen floor and require regular maintenance to prevent clogs and backups. The maintenance frequency depends on the grease trap’s size and the amount of grease and oil being produced.

Clean and maintain your grease trap regularly to prevent your plumbing system from clogging and backing up. Failure to properly maintain the grease trap can result in unpleasant odors, drain backups, and costly repairs.

Although grease traps are excellent for kitchens, they will not trap sewer gases in showers.

b. TrapGuard

This product is more of a P-trap accessory than an alternative or replacement. Instead, it should be used with plumbing components like P-traps to ensure your system functions properly and stays safe.

TrapGuard prevents unwanted odors, insects, and gases from entering a building through floor drains. It is particularly beneficial in buildings that could experience seasonal or periodic water usage changes.

It is ideal for different buildings, including residential and industrial. Installing it is pretty straightforward and requires minimal maintenance, but you must maintain it since failure to do so can cause drain backups, costly repairs, and unpleasant odors.

Final Remarks on Do Showers Need P-traps?

The vital work P-traps work of keeping your bathroom odor free is why it is a requirement in plumbing systems. Your P-trap could be the issue if your shower starts emitting foul odors and water pools on your shower floor. Shower P-trap replacements and repairs are better done by licensed plumbers.

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