Toilet Flange Too High/ Low: Fixes to Lower or Raise & Correct Flange Height

When the toilet rocks at the base, there is leaking and a foul sewer gas odor coming from the base of the toilet, it is a sign that your toilet flange is not set to the right height. It may be too low/high.

A toilet flange that is too high or too low usually occurs after the installation of a new toilet floor, mostly when the tiles are changed. Flange installation issues after repair or replacement of related parts, especially the wax ring can also be culprits.

The following are details on the right flange height and what to do when it is too high or too low

Toilet Flange Too High-Causes how to Lower

The two most common causes of an extremely high flange include wrong-sized flooring materials and a too thick/thin wax ring. Using the wrong flange type can also result in high flange height.

Toilet floor renovation

If you’ve recently had the floors in your bathroom replaced, then there is a chance that your toilet flange is now sitting too high. You may notice that a portion of the toilet still reaches the floor, but not the entire base.

The problem occurs when the toilet tiles or flooring material used is less thicker than the one before thus altering the toilet flange level leaving it sitting higher

Wax ring size

Another reason your toilet flange may be too high is the presence of a thicker-than-necessary wax ring, which you should consider replacing with a smaller one.

This is also a problem that commonly occurs after a toilet floor renovation where the previous installation was possibly thicker and thus installation of a less thick floor may cause the toilet flange sitting higher than it should.

How to Lower your Toilet Flange

Following are ways you can lower a toilet flange that is too high.

Use of Grout

Using grout to fill the gap between the toilet floor works pretty well to fix the problem of a toilet flange problem and prevents the toilet from rocking.

Below is the procedure you should follow to apply the grout:

  1. Start by mixing the grout in a small container using a 6:1 grout to water ratio after approximating the required amount.
  1. Get your toilet in place and set your toilet on four rubber shims. These rubber shims will keep your toilet from moving while you’re working on the flange.
  1. Take your mixed grout and pack it into the gap. Make sure you do this all around the toilet. And Wait for 24-hours for the grout to dry. To speed up the curing process you can spray the grout a few times in the day using a water spray bottle.
  1. Once dried, remove the shims. Some of these might be a little hard to remove, but they will eventually come out.
  1. After you have removed the shims, fill the gaps where you pulled the shims out from with more grout and leave to cure as in the first instance.
  1. After the grout has hardened, tighten the nuts holding the toilet down to the floor making sure not to apply excess pressure because the porcelain parts might break or dislodge or crumble the group by compression.

Raising the Bathroom Floor

Before you begin raising the bathroom floor you should keep in mind that this is a very time-consuming project. You might want to think about the other possibilities first. If you do decide to go this route, however, you’ll need to invest in a thicker type of flooring.

It’s simply a matter of adding thickness to your floor to raise it. To begin, determine how high the toilet flange currently sits above the bathroom floor. When you have a precise measurement, go to your local flooring or home improvement store and buy tile in the thickness you require. You can now take off the old flooring and replace it with new flooring.

Trim the Waste Pipe

Another fix to lower the flange height is to remove the flange with the toilet, then trim down the waste pipe that comes up through your bathroom floor. Ensure that the opening of this pipe is at the same level as the floor.

Toilet Flange Replacement

 Another feasible solution is to replace the existing flange with another of the right height.

Once everything is in place. The toilet should sit perfectly without rocking or leaking

Toilet Flange

Why is my Toilet Flange too Low?

 Floor Replacement/Re-tiling Issues

Another thing that might lead to your toilet flange being too low is retiling or replacement of the floor.

When re-tiling or setting new mortar on the floor, the gap between the top of the pre-existing toilet flange and the surface of the new floor surface might lengthen depending on the thickness of the tiles or the choice of material used thus leaving the toilet flange low.

Use of tiles or flooring materials that are thicker than the ones installed previously can cause a too low flange.

This affects compatibility of the attachment between the flange and the toilet drain pipe thus leading to leaks of both toilet water and sewer gas.

Worn-out Wax Ring

If you had previously installed a wax ring to space and waterproof the connection between your toilet flange and the toilet drain pipe, the wax ring might compress over time thus affecting the compatibility between the two leading to leakage of waste toilet water.

Sometimes a low toilet flange problem could be the fault from the previous installation. The plumber might have used a bad choice of a wax ring, that is, installed a less thicker ring where he was supposed to use a thicker one to raise the toilet flange level.

How to Raise your Toilet Flange that is too low

There are several ways to raise your toilet flange to prevent leakage problems due to incompatibility.

Some of the most common ways include:

  • Use of wax rings
  • Installing toilet flange extenders and spacers
  • Retiling

Use of wax rings

Wax rings are low-cost rings that fit around the toilet flange’s edge and seal the toilet’s bottom to the waste opening. They’re usually made of wax, but some modern versions use rubber.

The choice of wax rings to use when raising your toilet flange depends on the gap/distance between the existing toilet flange and the surface of the floor.

Wax rings come in different thicknesses thus you should choose one that fits as required. That is, one that sits about a quarter inch above the floor level.

The best way to bridge a large distance between the flange and the toilet is usually to remove the existing wax ring and replace it with an extra-thick one.

In some cases when the gap is quite large, you might have to use a double wax ring to compensate for the gap.

To install the new wax ring you have to remove the toilet by first, turning off the water supply, empty the tank by flushing and then empty the bowl. Unscrew the bolts attaching the toilet to the floor, then pull the toilet straight up and place it aside at a safe place away from the working area.

You’ll probably notice the old wax ring stuck to the flange after pulling the toilet. If not, it’s stuck at the toilet’s bottom. In any case, you’ll need to scrape it all off with a putty knife to get rid of it and prevent interference with the new replacements.

Place the new wax ring on top of the existing toilet flange and if the height is satisfactory, reattach the toilet and screw it back in place.

Use of Toilet Flange Extender/ Spacer

A toilet flange extender fits over the existing flange to raise the drain connection in relation to the surrounding flooring. Some flange extenders are plastic rings that come in various thicknesses.

Others are very similar to a standard floor flange but have a slightly smaller pipe stub that fits inside the opening of the existing flange. Some include a special flange and several plastic spacer rings of different thicknesses to accommodate different flange heights

Most extenders are secured by fastening them to the subfloor with screws driven through the holes in the old flange. To create a watertight seal, extenders include a rubber gasket or require sealing with caulk when they are installed.

To install a toilet flange extender, detach the toilet first by following the same procedure as when installing the wax rings then placing the toilet in a safe place.

Measure the distance between the top of the toilet flange and the top of the finished tile floor, then look for or buy a toilet flange extension ring thick enough to raise the toilet mounting surface to about 1/4-inch above the finished tile floor’s level.

Clean the top of the existing toilet flange thoroughly with a rag and scrape any foreign unnecessary materials off.

Apply a thin bead of silicone caulk around the top edge of the flange and then Place the extension ring on top of the flange and align the mounting holes so that they are above open spaces in the flange while maintaining the correct positioning of the toilet bolt slots.

Attach the extension ring by driving stainless steel wood screws through the mounting holes into the subfloor through open spaces in the flange.

Insert new toilet bolts into the slots in the extension ring. Slip on the plastic retaining washers. Place a new wax ring on top of the extension ring and then proceed with the toilet installation.

Re-tiling/ Lowering the Toilet Floor

As is the case when fixing a toilet flange that is sitting high above the floor by the installation of thicker flooring material, you can also raise the toilet flange height by installing less thick height to fix a to raise your toilet flange.

This process is expensive, laborious and time-consuming and should be considered as a last resort when raising your toilet flange.

What is the Maximum Height of the Toilet Flange above Floor?

The ideal flange height is 1/4 inch (0.64 cm) above the finished floor. With this height, you can use any of the common wax ring types without worrying about a possibility of a weak seal.

With this height, you are assured of a watertight seal between the flange and the wax ring on the underside of the toilet, which fits between the drain opening and drain outlet (horn).

However, the height may vary depending on tiling or flooring and the type of toilet you’re dealing with.

Just as important as flange height is getting the flooring material flat where the toilet base will go. Any time you have flange high, ensure the toilet is properly supported/shimmed so that it doesn’t rock.

Can the Toilet Flange be Lower than the Floor?

Yes, the toilet flange can be lower than the toilet floor but that shouldn’t be more than a quarter-inch below the toilet floor level. It is not recommended to have your toilet flange sitting low because you have to put extra labor and materials to fill the gap between the flange and the toilet.

Failure to do so may result in water seeping under the toilet and into the floor, gurgling noises from the drain, and a slow-draining toilet. It can also cause water to back up from the drainpipe into the toilet bowl. This can cause the toilet to overflow and damage the flooring around the toilet.

Tips to Ensure the Flange is Set at the Correct Height.

  • Always lay your flooring before you installing the flange. It’s easier to get your flange flush with the floor this way
  • Use the right flange type.
  • Follow the instructions when replacing specific flange types.
  • Replace worn-out wax rings.

Further Reading

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