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Toilet Flange Height: How a Few Inches Make a Big Difference

I bet you are wondering what a toilet flange is. It does not sound like something you want to entertain. When you think of bathrooms, toilet flange sounds like something you need to be cautious with, right? 

No need to worry. We will define what a toilet flange is, why you need one, what the toilet flange height should be, and how to install one.

A toilet flange prevents liquids and sewer gas smells from escaping your toilet. The appropriate height is level with your floor.

Toilet Flange Height

What Is a Toilet Flange?

A toilet flange is a small circular piece that connects your porcelain throne to the sewer. The flange is a vital component because it creates a seal that helps keep your home free of sewage gas and backflow.

If your flange’s installation is faulty, it could result in a leaking toilet or one that rocks back and forth. A leaking toilet may cause the surrounding components and flooring to mold and rot. It can also make the toilet loose enough to break or fall over. 

While a toilet falling over sounds embarrassing, a loose toilet can be dangerous and lead to injuries. Plus, mold and mildew from a leaking toilet can make you sick. 

You do not want to have strange bathroom accidents that result in a lot of repair work or a trip to the hospital. It is better to do things right the first time.

Things to Know Before Installing a Flange

For the safety of everyone, you must properly install your toilet flange. Here are a few things you should know to safely install your toilet flange.

Proper Fit

Check proper building codes to see the specifications for your toilet. Building codes dictate how far your toilet should be from the wall, giving you a starting point for installation. 


Before buying a flange, you need to know the size. The standard size for a toilet flange is four inches in diameter, but there are different sizes. 

You should measure the existing flange before purchasing a replacement. Double-check that your flange package comes with a wax ring. If not, you will need to purchase one according to your measurements or use silicone caulk to help create the seal. 


According to plumbing standards, the proper toilet flange height is level with the flooring. Accomplishing this is easiest if you lay your flooring before installing your flange. 

Installing a Toilet Flange

There are a couple of routes to install a new toilet flange. You can hire a professional plumber or install it yourself. Installing it yourself is easier than you might think and would save you money.

So, if you took all the previous precautions, you have all the right equipment to install your flange. The first thing to do is place something absorbent, like newspaper or cardboard, on the bathroom floor. 

Then you will turn off the water supply to the toilet. The water supply pipe is the pipe directly behind your toilet. Once you cut the water supply, flush the toilet several times to empty all the water.

After siphoning the water out of the toilet, disconnect the water supply hose. When detaching the hose, have a towel nearby. Some water will come out of the hose. Keep things as dry as possible to avoid slipping accidents.

Installing a Toilet Flange

Now, look at the base of your toilet. On each side, you should see a nut. Most times, these nuts have a cover on them as these two nuts ground your toilet to the flooring. You want to ensure you remove each one. 

Accomplishing this by hand is almost impossible, so use a wrench.

You will also find washers at the base of these nuts. Remove those as well, but put them to the side as a backup. 

Your new flange set should have washers, nuts, and bolts. If they do not have them, use the previous ones if they are still in good condition. Otherwise, make sure you are ready for a trip to the hardware store.

If you have made it this far, congratulations! Now, you are ready to remove the toilet. Most of us never think about the toilet installation process or its inner workings. The thought of all those loops makes me shiver, for sure. 

Toilets can be heavy. Some are over 100 pounds of (almost) pure porcelain. So, you may need a partner to assist you with lifting the toilet and placing it to the side. 

If you have to lift it by yourself, make sure you firmly place your feet shoulder-width apart and lift it with your back straight to prevent any back injury. Proper lifting is crucial to your health.

It does not matter how clean a bathroom is, toilets stink. So, once you remove the toilet, place a towel or t-shirt material into the outflow pipe to keep in sewer gasses, making your job easier and safer. 

You will see discolored wax around the flange, and it sits directly on top of it and seals the space between the flange and the toilet. The wax may be stuck, but you can remove this wax with a putty knife.

Once it is clean, remove the four screws on the flange and pull it out of the outflow pipe. 

You will work in reverse to install a new flange. Take the new flange, put the bolts on, and slip it into the outflow pipe. Screw the bolts firmly so that the flange fits level with the flooring. 

Turn the toilet to the side and put the wax ring on the bottom of the toilet opening. Place your toilet on top of the flange and screw the bolts so the toilet firmly fits with no wiggle space (if you think there’s nothing to screw the flange to, read here)

For aesthetics, place the covers back on the bolts. It is best to then test your installation with some quality assurance. 

First, connect the water hose. Then flush the toilet to see if there is any leaking from the bottom. Press on the toilet to see if it rocks back and forth. Once you have tested the toilet and you know your installation is secure, pat yourself on the back.

You’ve done it! Reconnect the water supply and turn on the water so the toilet will fill up.

Toilet Flange

What if the Flange Is Not the Right Height?

If your toilet flange installation is faulty, you will know immediately. If the toilet flange height is too high, the toilet may leak from the bottom, meaning that the flange and wax ring is not sealed. 

Also, you may sit on the toilet and notice that it rocks. A rocking toilet can break your flooring, costing you more money to repair your floor and possibly reinstalling your flange. 

So what can you do if your flange is too high?

  • You can raise your floor. You can do this by purchasing a thicker tile and building it up. This is time-consuming and takes a lot of calculations to do it properly.
  • Fill the space between the floor and the toilet with grout. It will take about 24 hours to dry. After this, you can sand it to smoothen the rough places.
  • You can trim down the waste pipe. It takes lifting the toilet and sawing down the waste pipe so it is level.

So, now you know what to do if your toilet flange is too high. But what do you do if your flange is too low?

Many houses built today install the flange before the flooring is complete. The result is a flange that sits under the floor. When the flange is below the floor, the seal is not appropriately placed and sewer gases will escape. This is unhealthy. So, resolving the issue is a must.

You have four options to fix a flange that is set under your floor:

  • Use two stacked wax rings instead of one.
  • Use an extender, which is like a funnel from the toilet bowl to the flange.
  • Use spacers, which are PVC rings that you can stack to match the floor’s level
  • Sani Seal is a polyurethane doughnut-shaped foam ring that replaces stacked wax rings.

Although most of us have never seen a toilet flange, it is a vital part of our bathroom experiences. You cannot use the bathroom safely or comfortably if you incorrectly install the flange. If you put in a new toilet, then you or your plumber will install a new flange. 

Ensure you install the flange after any flooring renovations are complete, and ensure it is ¼ inch above the flooring.

With a flange ¼ inch above the flooring, your toilet should fit snugly and flat to the floor. Remember, we don’t want any rocking or wobbling when you’re at your most vulnerable.

Remember, the signs of an incorrectly-installed flange are:

  • Leaking from the bottom of the toilet
  • Sewer gas smells
  • Toilet rocking back and forth.

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