Play it safe by becoming an expert on toilet flanges before replacing old flanges. Learn how to install a toilet flange--an easy DIY project.
Moving, leaking or clogged toilets? Never ignore a toilet that is trying to tell you something. Repairing a “sick” toilet could be as simple as replacing the flange. A toilet flange connects a toilet to drainpipes leading to the outside sewer. Flanges also securely attach a toilet to the floor so that toilets do not rock back and forth, leak or overflow.
It’s helpful to learn about the different materials and sizes of flanges before replacing a damaged one to ensure it’s the right flange for your toilet. Choosing the correct toilet flange means all the difference between a worry-free toilet and a toilet that demands your time and attention for a second time.
Table of Contents
- Types of Toilet Flanges
- Toilet Flange Sizes
Types of Toilet Flanges
Copper Toilet Flanges
Durable and corrosion-resistant, copper toilet flanges can be soft and flexible or rigid. Hard copper flanges may require elbow joints for proper fitting into a drainpipe. Copper is an anti-bacterial (biostatic) material used to make many plumbing components, especially components delivering potable water to communities.
Brass Toilet Flanges
A zinc and copper alloy, brass is a rust-resistant, malleable and resilient plumbing material excellent for use in making toilet flanges. Brass toilet flanges are available in the deep seal, offset and regular-sized flanges. Some simple circular flanges while others have an elbow joint attached that are designed to connect to drainpipes.
Plastic (PVC) Toilet Flanges
Plastic or polyvinyl chloride (PVC) toilet flanges are the most commonly used flanges in both residential and commercial toilets. Some PVC toilet flanges are made of 100 percent from polyvinyl chloride while others will come with a metallic top and a PVC base. All PVC toilet flanges are manufactured to fit three-inch or four-inch drainpipes.
Stainless Steel Toilet Flanges
Corrosion and rustproof stainless-steel flanges offer more durability and better sealing than PVC flanges. Like brass and copper toilet flanges, stainless steel flanges are more expensive than plastic toilet flanges.
Cast Iron Toilet Flanges
Meant to use with cast iron pipes only, cast iron toilet flanges are extremely sturdy, providing years of use without cracking or disintegrating. Designed for drainpipes existing beneath a toilet’s sub-floor, cast iron flanges can sometimes be repaired instead of replaced, depending on how serious they are damaged.
Aluminum Toilet Flanges
Aluminum is a lightweight, erosion-resistant, strong material used to make a variety of plumbing components. Unadulterated (pure) aluminum flanges are more durable than composite aluminum flanges infused with copper, zinc, and manganese. However, adulterated aluminum toilet flanges are still considered a good choice as a long-lasting, solid flange.
Toilet Flange Sizes
3″ Toilet Flanges
A three-inch toilet flange has a bottom and top that are exactly three inches wide. They can only be installed to a three-inch bend or a three-inch diameter drain pipe. If you start installing a three-inch flange pipe and discover the pipe is not three inches, you will need to position a reducing bushing to make the flange fit. However, installing a reducing bushing means the flange’s position is forced to rise unnaturally, which could affect the alignment of the toilet’s plumbing.
4″ x 3″ Toilet Flanges
A 4″ x 3″ toilet flange has a four-inch topside and a three-inch bottom diameter. The bottom of this size flange will fit standard-sized drain pipes. In addition, a 4″ x 3″ toilet flange is the size of most closet bend pipes. If you are not certain about your toilet pipe size, this flange would be appropriate to use.
Other Sizes of Toilet Flanges
Non-standard toilet flanges are similarly sized to 4″ x 3″ flanges. For example, plastic flanges are available with 7″ top and 3 1/2″ bottom diameters. To adapt to new floor installation, extensions kits are also available that raise a toilet flange above the new floor. When replacing a round toilet with an elongated toilet, you can purchase offset toilet flanges providing diagonal set openings that offer additional space to accommodate the bottom shape of an elongated toilet.
Push-Tite Toilet Flanges
Easy to install push-tite flanges simply need to be pushed in to securely fasten to the floor. They have gaskets that seal inside pipes and can be used with extra-heavy piping as well. Gaskets are made from engineered elastomer and are heat and chemical resistant.
Where Can You Buy Toilet Flanges?
The best place to find a variety of toilet flanges is a home hardware store or Amazon. Department stores carry toilet flanges but they won’t have the variety offered by Amazon, Home Depot or Loew’s. To avoid buying the wrong toilet flange, remove the toilet from the floor and examine the old flange. Depending on the flange’s material and how badly it is damaged, you might consider opting for a sturdier copper, stainless steel or brass flange.
What Kind of Wax Ring Should Be Used When Installing a Toilet Flange?
Wax rings are seals placed between the flange and the toilet to prevent leaking. Weight pressure exerted onto the wax ring by the toilet expands the ring so that it quickly forms an effective seal against water leakage. You don’t need to worry about getting the correct size of the wax ring because they are a “one size fits all” component. Some wax rings come with an attached polyethylene or rubber piece that extends into the opening of a toilet flange. Booted wax rings should not be used with toilet flanges that are high enough to prevent the toilet from sitting level on the floor. For flanges that are a little low, thicker wax rings will adequately fill any minimal extra space.
How Can You Tell a Toilet Flange Needs To be Replaced ASAP?
Toilet is Loose
If your toilet rocks even a little, it could be due to a damaged flange. Before removing the toilet from the floor, check all connections and bolts to ensure they are tight. Neglecting to secure a loose toilet could damage a flange that may not need to be replaced.
The toilet is Leaking at the Base
In most cases, it is the wax ring that needs replacing if your toilet leaks at the bottom. But to be sure, remove the toilet to inspect both the flange and wax ring. Never attempt to “seal” the toilet leak with some kind of sealing material that prevents water from leaking. While the water may no longer be leaking onto your floor, it is leaking somewhere and that somewhere is underneath the floor.
Don’t Know When and If the Flange Has Ever Been Replaced
Proactively avoiding expensive home or commercial building repairs means replacing questionable plumbing components. If the previous owner says they never had any problems with the toilet, chances are the toilet flange and wax ring are old and nearing their end life.
Your Bathroom Smells Like a Sewer
Rotten egg or sulfuric odors in your bathroom without leakage at the base of your toilet could mean the flange is broken just enough to let sewer line odors to infiltrate your bathroom. If not replaced, a cracked flange will eventually allow water to leak from the bottom of the toilet.
How to Remove a Toilet Flange
It’s easy to remove a flange but not so easy to move a one hundred pound toilet off the drainpipe. In addition to screwdrivers, adjustable wrench, putty knife and a shop vac to clean up afterward, you might need someone to help you move the toilet to avoid damaging floor tile–or your back!
- First, turn off the water supply to the toilet. Turn the knob behind the toilet clockwise to turn off the water. Most toilet water supply knobs are located close to the baseboard.
- Flush the toilet repeatedly until the tank and toilet bowl are both empty. If you can’t get all the water out, use a sponge to soak up any excess water.
- Remove nuts at the base of the toilet with the adjustable wrench. Nuts are located on both sides of the toilet.
- Once nuts are removed, begin gently and slowly rocking the toilet to disengage the wax seal. (This is where you will need assistance).
- Once you’ve broken the seal, lift the toilet up off the floor and move it aside.
- Scrape away the wax seal using a putty knife. Also, scrape off any wax seal sticking to the toilet’s underside.
- Unscrew the toilet flange to remove it. Save screws that are in good condition. Use new ones if the old screws are corroded or ground down. Old or badly damaged flanges may need to be pried out using a hammer and chisel. In some cases, really stubborn flanges should be cut and pieced using a power tool. After completely removing the old toilet flange, use your shop vac to clean away debris.
- Take the old flange with you when buying a new one at a hardware store. If shopping online for a new flange, measure the bottom and top diameters to ensure you order the correctly sized flange
How to Install a New Toilet Flange
There are two ways to begin installing a toilet flange:
- You can attach the new wax ring to the base of your toilet. To do this, you will need to lay the toilet on its side. This method ensures the wax ring is properly positioned when you put the toilet atop the flange. Or,
- You can put the wax ring on the toilet flange before putting the toilet back on top of the drainpipe. Remember, if the floor has been replaced since the last time the flange was changed and the flooring is made of denser material, you will need to use a thicker than average wax ring.
- Once the wax ring is in place, fasten down the new flange with mounting screws and bolts. Give each bolt an extra twist to make sure they are tight.
- Carefully replace the toilet on top of the new wax ring and flange. Align the toilet’s bolt holes with flange bolts. Gripping the inside rim of the toilet bowl instead of the outer rim will help you grip the toilet more securely.
- Once you have lowered the toilet down on the wax ring and flange, apply pressure to expedite sealing. Try not to tile or move the toilet after the wax seal is sitting on the flange. This might compromise the seal and promote premature leaks.
- Tighten nuts onto bolts at the base of the toilet. Don’t tighten them too much or you could crack the porcelain.
- Set the toilet tank on top of the toilet and align bolt shanks with holes in the toilet bowl.
- Tighten tank bolts until the tank is in contact with the toilet bowl
- Slowly turn the water supply back on and let the tank fill completely. If you see any sign of leaking at the bottom of the bowl, turn the water supply back off. If no water leaks, flush the toilet twice. Of course, is any water leaks from the bottom after flushing, you will need to remove the toilet again and check to see if the wax ring is positioned correctly or if the flange is loose.
Special tools designed to remove rusty or broken toilet flanges are available when a simple putty knife just won’t get the job done. Essentially an internal pipe cutter, flange-removing tools typically feature a circular saw appended to a shaft. This shaft then should fit into any standardized drill chuck. Solvents are sometimes used to remove old flanges but solvents containing certain chemicals could cause pipe erosion. Check for the possibility of a chemical reaction by researching solvent ingredients and pipe material before using solvents.
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