Toilet Flange

Toilet flange

In the realm of bathroom fixtures and plumbing, one often overlooked yet indispensable component plays a crucial role in maintaining the seamless functionality of our toilets – the humble toilet flange. While it may not garner the attention that gleaming faucets or stylish tiles do, the toilet flange is, without a doubt, the unsung hero that ensures a secure and efficient connection between your toilet bowl and the sewer pipe beneath.

In this article, we embark on a journey to explore the significance of the toilet flange, shedding light on its vital role in the proper functioning of your bathroom and the consequences of neglecting this unassuming yet vital piece of plumbing hardware. Join us as we delve into the depths of the bathroom plumbing system to unravel the secrets of the toilet flange and understand why it deserves its place in the spotlight.

What is a toilet flange?

Types of toilet flange

Copper toilet flange

Copper Toilet Flange

Copper stands out as a distinctive metal due to its capability to form various alloys when combined with other metals, resulting in a range of advantages. These advantages encompass enhanced conductivity, increased strength, and heightened corrosion resistance – a crucial attribute for all types of toilet flanges. Moreover, copper is relatively cost-effective to manufacture, making it a popular choice for various plumbing applications.

PVC toilet flange

PVC Toilet flange

PVC, a plastic material, is employed in the production of flanges. Initially developed by Bayer in Germany in 1872 for medicinal purposes, PVC has found widespread use in the creation of toilet flanges for both residential and commercial plumbing systems. PVC toilet flanges exist in different forms, either entirely composed of PVC or featuring a metal top. These flanges are designed to fit drainpipes measuring three or four inches in diameter.

Brass toilet flange

Brass Toilet Flange

Among the commonly utilized materials for toilet flanges, brass shares similarities with copper in terms of malleability and resistance to corrosion. These qualities make brass an excellent choice for those seeking a durable toilet flange.

Cast Iron toilet flange

Cast Iron Toilet flange

Designed specifically for use with cast iron pipes, cast iron flanges boast exceptional durability and resistance to damage. In certain instances, it may be feasible to repair a cast iron flange instead of opting for a complete replacement.

Aluminum toilet flange

Aluminium Toilet flange

Renowned for its lightweight nature, corrosion resistance, and durability, aluminum stands as a commendable option for toilet flanges. This metal does not succumb to rust or corrosion, ensuring a prolonged lifespan before necessitating replacement. Aluminum flanges are available in pure aluminum or in variations that incorporate copper or zinc. While pure aluminum types are generally preferred, both varieties are suitable for use in toilet applications.

Sizes of toilet flange

Various flange sizes are available to accommodate pipes of different dimensions. If you are unfamiliar with the installation of these flanges, it is beneficial to acquaint yourself with their specifications.

Typical 4 x 3-Inch Toilet Flanges

The most prevalent and easily accessible toilet flange size is the 4 x 3-inch variant. This flange has a 4-inch width at the upper section and a 3-inch width at the bottom. The 3-inch bottom dimension aligns appropriately with the schedule 40 pipe commonly utilized in residential drainage systems. The 4-inch top provides a slight buffer, minimizing the risk of water seepage through the wax ring during toilet flushes. It’s noteworthy that this size corresponds to the typical dimensions of the closet bend pipe in most instances.

3-Inch Flange

A flange with a three-inch diameter corresponds to the size of the schedule 40 pipe commonly employed in toilet drains. Unlike the 4-inch flange, the 3-inch version provides less leeway, resulting in increased pressure on the flange during toilet flushing. Despite this recognized issue, 3-inch flanges are designed to withstand the additional stress.

When installing this type of flange, it is essential to ensure that your piping is the correct size. If your drain does not utilize a 3-inch pipe, it is advisable to opt for a different flange. While it is possible to use a reducing bushing to connect to a smaller pipe, this elevates the position of the flange and may impact the overall alignment of the plumbing system.

4-Inch Flange

The 4-inch flange is designed to be compatible with both 4- and 3-inch drainpipes. This type of flange is crafted to either fit over the top of a 3-inch pipe, where the pipe slides into the flange, or to fit inside a 4-inch pipe, with the flange sliding into the 4-inch pipe. This versatile flange is suitable for situations where uncertainty exists regarding the size of toilet pipes or when the installation of a drainpipe is required between the flange and closet bend, preventing a direct connection between the two.

Unconventional Flange Sizes

There are flanges available in unique sizes. Generally, these flanges share similarities in size with the 4 x 3-inch variant. An example includes an ABS plastic flange featuring a 3 1/2-inch bottom diameter and a 7-inch top diameter. This particular flange is frequently employed to establish a connection between an ABS drainpipe and the toilet.

When to Replace a Toilet Flange

Now that you’re familiar with the various types of toilet flanges, if you’re uncertain about the last time your flange was replaced, you have the option to continue using it until it fails. However, for those who prefer to avoid potential issues, replacing it proactively is a wise choice. A deteriorated flange can lead to a range of problems, including:

  • Leakage at the toilet base.
  • A wobbly and insecure toilet that rocks back and forth.
  • Unpleasant odors emanating from the sewer due to gas leaks through the seal.

Should you observe any of these indicators, it is advisable to consider replacing your toilet’s flange sooner rather than later.

How to Remove a Toilet Flange

While removing a toilet flange is relatively straightforward, handling a heavy toilet requires extra care to prevent damage to the floor or injury to yourself.

  1. Turn Off the Water Supply:
    Locate the water supply knob behind the toilet, typically near the baseboard.
    Turn the knob clockwise to shut off the water supply completely.

  2. Empty the Toilet:
    Flush the toilet repeatedly until both the tank and bowl are empty.
    If there’s residual water, use a sponge to absorb it.

  3. Remove Closet Bolts:
    Using an adjustable wrench, locate and loosen the closet bolts at the toilet’s base.
    There are usually two nuts on either side of the toilet.

  4. Disengage Wax Connection:
    Gently rock the toilet back and forth to loosen the wax connection.
    This step might require assistance to avoid damaging the floor tiles.

  5. Lift and Move the Toilet:
    Once the wax seal is broken, carefully lift the toilet straight up.
    Move the toilet aside, placing it on a protected surface.

  6. Scrape Off Wax Residue:
    Use a putty knife to scrape away any remaining wax from the floor and the bottom of the toilet.

  7. Unscrew and Remove Flange:
    Locate and unscrew the screws securing the flange to the floor.
    If the screws are corroded or damaged, replace them with new ones.

  8. Remove Stubborn Flanges:
    For old or damaged flanges, use a hammer and chisel to pry them out.
    If the flange is particularly stubborn, use a power tool to cut and remove it.

  9. Clean Up Debris:
    Thoroughly clean the area with a shop vac to remove any debris.

  10. Measure and Buy New Flange:
    Bring the old flange to the hardware store to ensure you purchase the correct size.
    If shopping online, measure the bottom and top diameters of the old flange.

How to Install a New Toilet Flange

  1. Lay the toilet on its side.
  2. Place the wax ring on the base of the toilet.
  3. Return the toilet to its upright position and align the bolt holes with the flange bolts.
  4. Lower the toilet onto the ring and closet flange, applying pressure to expedite sealing.
  5. Tighten the nuts onto the bolts at the base, but do not overtighten.
  6. Set the tank on the bowl and align the bolt shanks with the holes in the bowl.
  7. Tighten the tank bolts until the tank is in contact with the bowl.
  8. Turn the water supply back on and let the tank fill completely.
  9. Flush the toilet twice.
  10. Check if there are leaks, if not, congratulations! The installation is complete.


In conclusion, the often-overlooked toilet flange plays a pivotal role in maintaining the integrity and functionality of our bathroom plumbing systems. From securing the toilet to the floor to establishing a vital connection with drain pipes, the toilet flange serves as a silent guardian, ensuring a seamless flushing experience. As we’ve explored the various types, including copper, PVC, brass, cast iron, and aluminum, it becomes evident that the choice of material significantly influences the durability and performance of the flange. Additionally, understanding the diverse sizes, such as the standard 4 x 3-inch flange and its versatile 4-inch counterpart, enables homeowners and plumbers alike to make informed decisions during installations or replacements.

Whether opting for the conventional 3-inch flange, accommodating the schedule 40 pipe, or exploring odd-sized flanges for unique plumbing configurations, the importance of proper sizing cannot be overstated. An accurate match between the flange and the toilet model, as well as the characteristics of the piping system, ensures a reliable and watertight connection.

As we navigate the intricate world of toilet flanges, it becomes evident that their significance extends beyond mere functionality – they contribute to the overall longevity and efficiency of our bathroom fixtures. By staying informed about the role, types, and sizes of toilet flanges, homeowners empower themselves to make informed decisions that can enhance the durability and reliability of their plumbing systems, ensuring a trouble-free bathroom experience for years to come.

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