Shower P-Traps: What Are They And How To Remove Them

Ossiana Tepfenhart
by Ossiana Tepfenhart

If you’re new to the world of plumbing, one of the first things you will probably learn about is P-traps. While they are common in toilets, they are also ubiquitous in showers, sinks, and more. The thing is, P-traps sometimes need to be replaced, especially if you’re looking to do an overhaul on your plumbing. So, what’s the deal here?

P-traps are curved pipes that direct wastewater out of your home and prevent the smell of sewage from entering your bathroom. All plumbing fixtures need a P-trap. It’s located close to your shower drain. To remove it, you will need to cut through the subfloor and pull it out.

Understanding what your P-trap does is vital to your ability to keep your plumbing sanitary, not to mention improve your flow. If you’re having troubles with your drainage system, keep reading. We’ve got all the answers to the questions you’re afraid to ask.

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What Does A P-Trap Look Like?

A P-trap is a curved pipe that kind of looks like a capital “P” without the bridge across the curved portions of the pipe. It’s composed of three different parts: the inlet, the downward bent, and an outlet. It is this specific curved shape that helps trap gasses and backflow from re-entering your shower.

Where Do You Find Your Shower’s P-Trap?

A shower P-trap is typically found close to the drain, near the center of the shower. Most plumbers prefer to have the P-trap closer to the drain, simply because it makes the gas trapping aspect of this plumbing more effective. You can learn more about P-trap distances in our article on-site if you’re feeling a little lost.

Do Showers Need A P-Trap?

Absolutely. You will not find a building code ordinance that allows you to build a shower setup without a P-trap. Not having one in your shower setup poses a threat to your safety and sanitation. After all, you don’t want to inhale all that swamp gas, do you?

How Do You Maintain A P-Trap?

If you want to avoid having to remove your P-trap before you need to, it’s important to maintain your plumbing. The best way to do this is to give it an in-depth cleaning on a regular basis. To do this, open your shower drain and use a brush to scrub things down. You can loosen up grit and grime by pouring a mix of vinegar and baking soda down the drain.

Of course, if you have a drain snake, you can usually get better results with a faster scrub down. To ensure that you get the best possible results, you can also use a commercial drain cleaner once every three to six months.

How Can I Tell If I Need To Replace My Shower P-Trap?

Eventually, you will need to replace your shower’s plumbing for one reason or another. There are several major signs that you may need to replace your P-trap. The most common signs include:

  • Though you regularly rewet your P-trap, you still notice a stench in your bathroom. This is usually a sign that you have a broken water seal in or around your P-trap.
  • You’ve noticed signs of a leak coming from the bottom of your shower. A burst P-trap pipe is a terrible thing indeed! Do not use your bathroom until this is fixed. Using a leaky plumbing system can easily cause mold, mildew, as well as serious damage to your home’s structure.
  • Your P-trap regularly gets clogged, and your bathtub has experienced a lot of backups. Do you have water backups on a regular basis, despite regular snake sessions? Does it feel like your shower isn’t draining the way it once did? If cleaning didn’t work at loosening things up, you may need to replace it.
  • There has been serious damage done to your bathroom plumbing system. Any time there is damage from a flood, an earthquake, or other disaster, it’s best to try to replace your P-trap.
  • No matter what you do, your bathroom keeps smelling like a sewer. Sewer gas is toxic and microbe-filled. If you have a foul smell that won’t go away despite you wetting down the P-trap, you need to replace it. This is doubly true if you notice an infestation of drain flies that won’t go away.
  • It’s been over 15 years since you’ve changed your plumbing. Depending on where you live, plumbing can become highly susceptible to wear and tear after the 15-year mark. Sometimes, you just need an upgrade and there’s no shame in just giving your plumbing an overhaul.

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

A P-trap is one of the most important devices when it comes to preventing sewer gas from leaking into your bathroom. If your shower doesn’t have a P-trap, then the sewer gas will eventually seep into your home. This can pose a serious health risk, not to mention a risk to your nose’s wellbeing.

Moreover, if your shower doesn’t have a P-trap, chances are high that your home isn’t up to code. While there are some alternatives, the vast majority of regions will demand you have one. If you skip it, you should prepare yourself to be asked to redo your plumbing…and maybe pay a fine.

Why Would You Want To Remove The P-Trap?

The most common reason why you may want to remove the P-trap is because you want to replace it. Replacement is a must if you have serious clogs, if you have been getting water flooding back into your shower basin, or if you have reason to believe that your P-trap is leaking. Here’s how to remove it:

  • Grab an electric saw and cut the subfloor around your shower. You want to make a 12-inch by 12-inch hole. Make sure that you only cut the portion running over the floorboards, otherwise you will not have a way to nail your new subfloor after the P-trap is removed.
  • Carefully pry the square of subfloor out using a prybar. You do not want to chip this, since you want it to be a clean cut with edges that are flush. This ensures your subfloor will fit back nicely post-replacement.
  • Cut the drain off right after the P-trap with a saw and pull the P-trap out. You may need to manually unscrew part of the drain from the shower in some builds. Throw the old P-trap away.
  • Attach your new P-trap. If you have a P-trap that is smaller than the rest of your plumbing, fix it by attaching reducer pipes to your outfit. If you use a reducer to funnel your drain’s water to the P-trap, choose a high-quality glue to create a “lock” on the pipe. Attach it firmly and make sure that you have placed the P-trap in the correct place.
  • Reattach your subfloor square, and measure the distance between the subfloor and the new P-trap. Measure out a piece of ABS piping equal to that distance, and cut it. Attach the ABS piping to the P-trap’s other end, making sure that you use plenty of waterproof glue to fit it in.
  • Replace the shower drain. Once you’ve wrapped things up, you can reattach the shower drain.

Should You Call A Professional To Replace Your P-Trap?

Replacing a P-trap is one of those projects that needs to be done perfectly, otherwise you’ll end up with a non-functional bathroom. Due to the complexity of the project, it’s best to call a professional plumber to replace your P-trap. This is especially true if you are not used to cutting through subfloor since this can wreck your bathroom.

In some areas, local building codes will require you to hire a licensed plumber for a P-trap replacement. If this is the case in your town, you don’t have a choice.

How Much Does It Cost To Replace A Shower P-Trap?

This all depends on your region as well as who you hire to replace the P-trap. Nationally, the average cost of a shower P-trap replacement rests around $315. However, it can be as cheap as $95 and as high as $880 in extreme circumstances. To get the best bid, make sure that you shop around for a contractor.

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Related Questions

Why does my shower drain smell like poop?

If your shower drain gives off a sewer-like smell, it usually has something to do with a P-trap issue. Most of the time, this is a sign that the water in your P-trap has dried out due to nonuse. To fix this, just run the shower for a short period of time and the smell should dissipate. P-traps need to be kept wet to function.

Does water sit in a P-trap?

Though it might come as a shock to people who are not in the plumbing world, yes, water does sit in your P-trap. It actually has to. Water is what creates the barrier that keeps the sewer gas and microbes from flooding into your home. This is also why keeping your P-trap wet is such a big deal.If a P-trap dries out, it loses much of its ability to prevent sewer gas emissions. However, it will not interfere with your system’s ability to prevent water backups.

Why are S-traps illegal in most parts of the country?

S-traps are a P-trap alternative that’s banned in most parts of the country. The reason for the ban is actually fairly simple. S-traps have a tendency of siphoning water out of the trap. This, in turn, can break the seal and release sewer gasses into your home. When given the option between a P-trap and an S-trap, always choose to install the P-trap.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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