S Trap or P Trap – Which Trap Type to Choose?

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Your old toilet bowl has stopped working and you are planning to install a new toilet bowl. Perhaps you think it is very easy – you just have to browse through the models from various brands (e.g., Baron, Saniton, etc.), select one, and get it installed. However, it is more than that. Giving importance to the toilet bowl alone is not enough, you also have to give attention to the drain traps. You have two options to select from – P trap and S-trap. We shall help you learn about it both in detail so that you can easily make a wise choice.


P Trap Toilet Bowl


P-trap toilet bowls have U-shaped pipes. They connect your drain to a sewer system or a home septic tank. The P-trap keeps holding some water to avoid any sewer gasses from moving into your home. Let us now learn more about a P-trap toilet bowl.


Installing a P-trap toilet bowl such as the Baron W-888 1-Piece Toilet Bowl is inexpensive and easy. There can be many kinds of PVC connections. If you want to install a P-trap toilet bowl, you need to have the required PVC couplings. This includes a wrench, compression nut, pipe tee, and elbow. Once you have the supplies, you need to begin installing the new P-trap. Generally, to make a P-trap, a hole is cut out in the floor drain and is attached to the drain.

Even though installing a P-trap toilet bowl is comparatively easy, it still would not be a good idea to try doing it on your own – especially if you are interested in installing it perfectly. Instead, you can take the help of a toilet bowl professional. One of the reasons why you should hire professionals to install your toilet bowl is due to them having years of experience and skills. The tools that you need for either an S-trap or a P-trap toilet bowl installation can be expensive too, but when you hire a plumbing professional, you will not have to worry about the unnecessary extra expense and enjoy perfect results.

Suitable Setup

A P-trap is suitable for the top floors. If you have an HDB flat somewhere on the top floors, then you can be sure a P-trap toilet bowl will ideally work for you. It is important to hire a professional plumber to install your HDB toilet bowl to avoid experiencing any toilet bowl issues due to improper installation.

Design Advantage


In P-trap designs, there is no looping over and going back down. Rather, it moves into a horizontal run and exits downward. This horizontal run guides the water into a 90-degree turn and forces it to go downward. This kind of design is more commonly found compared to the looping one because the water, in this case, enjoys a larger path. This is why a P-trap toilet bowl like the Saniton Camellia ST2488-SC3033 2-piece Toilet Bowl can easily manage a large amount of water.


A P-trap toilet bowl can quite consistently and effectively maintain water traps. Cylinders that have five rows and that come in four rows can be fairly compared. This is concerning the amount of water they receive. In the case of P-traps, the pipes with larger diameters can more efficiently catch water.

Backflow Prevention

The P-trap creates a natural water seal. Water may move into the overflow pipe but will not go back into the toilet bowl. The water seal present at the bottom of the trap prevents any backflows from happening. Thus, sewer gas does not enter the trap.

S Trap Toilet Bowl


An S-trap toilet bowl is like a P-trap toilet bowl, but it does not have a horizontal arm. It is known to curve down and go down again, thus forming an S-shape. The drainpipe is connected to the floor with the help of the drain pipe. Let us get to learn about an S-trap toilet bowl in detail.


S-traps are generally used on the ground floor, so they can be installed below ground level. Usually, PVC glue is used to install them but the pipes can also be joined without the use of glue. Installing S-trap is quite hard and can only be installed by plumbers. If you decide to install an S-trap (or P-trap) toilet bowl, then toilet bowl professionals can prove to be of great help. Each plumbing professional first undergoes rigorous training sessions and only then are they allowed to work for you. They are also highly experienced and known to offer timely toilet bowl services. Even if you are confused about whether you should opt for an S-trap or P-trap, then professional plumbers can help decide the right one. They will consider your requirements and flawlessly complete the toilet bowl installation.

Suitable Setup

An S-trap is suitable for ground floors. If you live on the ground floor and are trying to figure out which toilet bowl will be better for you, then you can go for an S-trap. You can opt for the Saniton Indica ST2999-SC3122 or the Saniton Melissa ST245 S-trap toilet bowls. If you are still confused, you can take the help of toilet bowl professionals for a better guide to buying your toilet bowl.

Design Advantage


An S-trap has a nice and straightforward design such as the Baron W-203A 2-Piece Toilet Bowl. The drainpipe moves down from the toilet and enters into a traditional trap. The drain similarly moves down from the sink and enters the trap. There is an issue with this design. Many people drop things into their toilet bowl apart from the human waste and this eventually blocks the drain.


S-traps can be said to be comparatively less effective because they are known to dry out. This enables the gasses to flow. Also, they are not easy to clean. You may need to replace the complete S-trap system and that can be costly. Furthermore, bacteria may build up in the S-trap toilet bowl thus causing common toilet bowl problems such as odor and comfort issues.

Backflow Prevention

The S-trap comes equipped with an air filter. It prevents any sewer gasses from flowing back into your home without completely getting rid of the sewer gas.

Choosing Between a P-trap Or an S-Trap


An S-trap and a P-trap toilet bowl are both used for the same purpose, but they are quite different. While deciding among the S-trap and P-trap toilet bowl – which is better for your home, it is very important to consider installation requirements as well as the risks.

S-traps are not allowed to be used anymore if you are remodeling a home or even in new construction. This is because an S-trap does not match the housing code requirement, so during an inspection, the inspectors will not likely approve of an S-trap.

The P-trap can prove to be a wise choice. The S-trap may let poisonous sewer gasses move into your home because of its design, something you certainly will not want. An S-trap may even let vermin move into your house if the trap remains dry for too long a duration.



If you are planning to install a new toilet bowl because your old toilet bowl has started to show issues like a toilet bowl leak, then you will have to select from a variety of toilet bowl products available in the market. Other than the toilet bowl brand, you will have to choose from an S-trap or a P-trap toilet bowl. It is important to know their differences, which are mentioned above. If you are looking to buy a toilet bowl, Everyhome Singapore offers a diverse range of toilet bowl brands and types that meets your needs. Additionally, do keep in mind that whichever type of trap you select, it is best to have it installed by a professional plumber as they are more knowledgeable about and experienced.


At Toilet Bowl City Singapore, we understand the need to keep home service expenses within your budget. Hence, we offer honest and reasonable pricing for any of your toilet bowl installation works. Select from our range of toilet bowl brands, browse our past toilet bowl installation projects for inspiration, or read up on toilet bowl-related articles to find out more about toilet bowl installation services. Get in touch with us now via WhatsApp at +65 8241 0032!