One Piece Vs Two Piece Toilet – A Comparative Analysis

Written by

Paulk Webb


Freddie J. Hagopian

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one piece vs two piece toilet

Comparing one piece vs two piece toilet is beyond appearance. You have to be particular with the three parts of the toilet which are the tank, bowl, and pedestal. The tank contains water and the bowl is where the waste passes through to get to the sewage system. Lastly, the pedestal determines the toilet’s height.

When you know the functions of the basic parts, you can integrate them into the bathroom fixture or toilet designs. A one-piece toilet is a single unit without crevices and joints. On the other hand, the tank and bowl of a two-piece toilet are separated.

Both of these toilets have the same water-saving capabilities and flushing mechanisms. However, there’s a difference between one-piece and two-piece toilets. It will help you decide which one you need for remodeling or taking out an old toilet and buying a newly constructed toilet.

Toilet Basic Information


As mentioned above, a toilet has basic parts and they are as follow:

  • Bowl: The bowl’s role is to catch the waste or pee to be sent to the sewer after.
  • Tank: This is the water storage and it operates when flushing is done. Pressure is essential to completely get rid of the waste.
  • Pedestal: It also refers to the holder of the bowl as it provides lift from the floor.

One-piece toilet – No necessary joint to connect the toilet and tank as it’s in one body or solid unit. Another term for this is ‘single piece toilet’. I would like to recommend Swiss Madison SM-1T254 St. Tropez, EAGO TB351, Kohler 3810-0 Santa Rosa Comfort Height, and American Standard 2034314.021 as they are bestsellers.

Two-piece toilet – The toilet and the tank are two separate pieces so fittings are needed to put them together. It’s also referred to as a ‘coupled toilet’. Kohler K-3999-o Highline Comfort Height, TOTO CST454CEFG, and American Standard 2889218.020 are the best for many.

1 Piece Vs 2 Piece Toilet: Factors That You Have to Consider


Weight and Size

One-piece and two-piece toilet types come in various sizes. Typically, the design of one-piece toilets needs less space because the toilet tank and bowl are molded after a complex production process. Thus, there’s no need for much room for its height or front and back parts.

On the other hand, the majority of two-piece toilets have a comfort height of 17 inches. But they’re still available in standard height. Note that these toilet types are in various sizes to match the designs of various bathrooms.

It’s also vital to check the rough-in of the toilet, the measurement from the wall to the center of the drain pipe. This part can be 10 or 14 inches but most toilets have a 12-inch rough-in.

The size of a toilet, whether it’s a two-piece or single-piece toilet, is based on toilet models. Being compact and space-saver is not only the abilities of a one-piece. Some modern, two-piece toilets are compact to fit limited bathroom space.

Amazingly, two-piece toilets allow alteration on their sitting due to the constant bowl size. You can order a different tank and replace the previous one to please your preference. Hence, there will be numerous options if you have an odd rough-in with a two-piece.

Although one-piece toilets prove to be heavy, they have a movable rough to match with different bathrooms. Just expect to pay a high shipping cost for moving. It’s the two-piece that allows disassembling before moving so it’s lighter. Moreover, shipping costs drop due to this reason.

Flushing Power

These toilets function through various flushing technologies that are integrated to their flushing systems. The low-flow versions that need as little as a gallon of water every flush are also available.


Both one-piece and two-piece toilets are not easy or difficult to install. There’s no significant difference in the amount of effort you need for installing each of them. You’ll find the same features and interior parts as well as the flushing mechanism, especially if they’re from the same manufacturer.

Despite the possibility of easily moving the two-piece, you need to spend some time bolting the two-piece counterparts. Assembling is not required for one-piece toilets.

Whichever type you have, you need to put the wax ring on the drain pipe. I would like to recommend the ring from DANCO, BOEEMI, Westbrass, and Prime Line as they’re patronized by many. When adding it, the toilet is set above the ring inclining at a slight angle as it curls sharply to face the front side.

In this process, the installer can sit on the toilet while evenly distributing the weight side to side for the right position. Furthermore, the toilet is stable on the floor with the help of bolts that are usually kept in the bolt caps or toilet skirt.

The water line is sealed and linked to the tank’s bottom. First, the water fills the tank before flushing to be able to inspect leakage. This is not a time-consuming installation as it only takes half an hour.

I need to remind you to be careful during installation. You may be in the situation of mounting a fragile porcelain tank on the toilet bowl. Over tightening of the bolts may lead to cracking. It’s better to hire a qualified plumber if you’re not sure of what you’re doing.


In terms of two-piece vs one-piece toilet durability, a one-piece water closet is advantageous because the coupling that holds the toilet bowl and the separate tank is prone to cracking. Replacement is required at some point.

Also, the rubber gasket located between the two sections of the old toilet tends to degrade. If not fixed, leakage can give you trouble. Luckily, the necessary repair is trouble-free and inexpensive.

No broken coupling or joining part would bother you when using a one-piece toilet as the whole unit is molded. But when misfortune occurs like when the china got broken in the tank section, you have to buy a new toilet. If it happens with two-piece, the broken part is replaced individually.

When it comes to replacement, the internal parts of these toilets sometimes need to be restored. You’ll need to do the same thing when the seat breaks but rest assured, it’s uncomplicated as it’s a separate accessory. Nevertheless, your toilet can serve you for 50 years or more of service without needing replacement if you give it proper care.


For toilets in one mold, the parts that connect the bowl and tank are seamless. Thus, they’re sleek with a modern feel. Your bathroom can get a luxury appearance. On the other hand, two-piece toilets deliver traditional looks due to the obvious separation of the tank and bowl.

Cleaning and Maintenance

With the previous factors that you have to consider, which is the better one-piece or two-piece toilet? You might have determined the right toilet for you at this point. Aside from putting effort into the installation process, you have to work on maintenance and cleaning.

In this part, the one-piece toilet wins over the two-piece since it doesn’t have hidden corners and joints. Germs and bacteria can’t hide in nooks and grooves. When cleaning one-piece toilets, you’ll usually wipe them to stop the accumulation of mold and bacteria.

You’ll be challenged to clean the two-piece toilets due to the joints and hard-to-reach places. Besides keeping the toilet clean, the growth of dirt and germs are tolerated by the nooks and crannies. You need to be attentive in cleaning them as not doing so will pose health hazards.

Can You Turn a One-piece Toilet Into Two-piece

Make a few, easy tweaks and you’ll have a two-piece toilet when necessary. Even so, the rough measurement should be the same. No changes should also be done to the bowl size. Thus, it would still fit in the bathroom’s dimensions.


This article revealed what you have to know about one piece vs two piece toilets. They have their own advantages and disadvantages. Be smart enough to choose the one that gives you more benefits and convenience. After all, your decision in this matter is mostly your personal preference.

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