Toilet Flange Height: How to Set and Adjust It

If you’re tired of a wobbly or crooked toilet, look no further. The incorrect toilet flange height is most likely your problem. Using the proper flange height ensures a long-lasting and leak-free toilet installation. If you find out that your flange is installed too high or too low, you can try the tips below to fix it.

What Is the Standard Toilet Flange Height?

The toilet flange is a circular ring that attaches to your drainpipe. This toilet part has two jobs: It prevents leaks and keeps your toilet securely bolted to the floor. Most flanges are made of PVC, although they’re also available in stainless steel, ABS (acrylonitrile butadiene styrene), copper, and brass.

The standard toilet flange height is 1/4 inch above the finished flooring, and installing the flange below or flush with the finished flooring leads to leaks. The easiest way to ensure you get this done right is by installing the flooring before the flange.

How to Set the Toilet Flange Height

The following steps will help you set the toilet flange at the right height. However, if you want a professional to step in, call a plumber who can perform an error-free installation. 

1. Install your flooring over the sewer pipe and then cut a circular hole to expose the pipe.

2. Apply pipe primer on the flange and the inside of the drainpipe.

3. Install the flange and press down until it sits at ¼ inch above the flooring.

4. Screw the flange to the subfloor (predrill holes if you have a cement subfloor).

5. Center and install the T-bolts on both sides of the flange. 

6. Install a wax ring or a wax-free seal.

7. Level the toilet on the flange and install toilet shims if it’s wobbling.

8. Bolt the toilet down.

9. Caulk the base of the toilet with silicone caulk.

If you use a wax seal, you can use an extra-thick wax ring if your flange sits slightly lower than 1/4 inch above the finished flooring. Avoid stacking wax rings because this makes your toilet more susceptible to leaks, but you can use a flange extender as an alternative. 

Waxless seals are available in PVC, rubber, or foam for easier installation. Some models will accommodate floors raised ⅜ inch above the flange, giving you more flexibility than traditional wax seals.

Common Toilet Flange Misalignment Issues and Solutions

Here are the most common toilet flange alignment problems and how you can fix them. If you’re short on time or prefer to hand this off to a pro, hire a toilet repair service near you to handle your flange installation. They’ll install the flange to the proper height with a tight seal. You can expect flange replacement costs to range between $145 and $165.

Installing a New Flooring Type

You’ve decided to rip up your old bathroom flooring and install something new. As exciting as that is, remember to take care of all the details to ensure your plumbing stays in good shape. 

Unless you’re installing the same material, your floor height will change. For example, laminate flooring is 8 to 12 millimeters thick (about 1/3 to 1/2 inch thick), while tile flooring is 1/2 to 3/4 inch thick.

A common mistake is forgetting to adjust the flange height and simply using the old height after installing the new flooring. This will eventually lead to leaks, which can cause expensive and extensive damage to your flooring, subfloors, walls, and more. Avoid this by fixing the flange height yourself or bringing in a pro to update your plumbing for the new flooring.

The Flange Is Too High

A common issue you’ll notice when the flange is too high is a wobbly toilet, which is not only super uncomfortable but also prone to leaks. One way to fix it is to use a hacksaw or an angle grinder and shorten the flange (use eye protection and earplugs). Otherwise, starting over from scratch and replacing it with a new toilet flange is best. 

If the toilet flange is too high because you installed new flooring, you may need to cut down the sewer pipe before installing the flange.

The Flange Is Too Low

Using a flange extending kit, you can fix a flange that’s too low. Most kits allow you to fix discrepancies around 1/4 to 1 5/8 inch. All you have to do is install a gasket and place as many spacers as needed to raise the toilet flange to the right height. Then, you can install the flange extender on top.

The Flange Is Off-Center

When you install the flange, you need to pay attention to where the toilet bolts go. They slide and lock into place, so if you miscalculate the orientation of the flange, you’ll end up with a toilet slightly angled toward one wall. 

If you have a crooked toilet, you’ll have to remove the toilet and fix the flange, requiring you to scrape off the wax ring or remove the waxless seal. Then, you’ll either remove the flange and reposition it or use a router bit to widen the length of the bolt holes.

To avoid repeating the same mistake, you can place the T-bolts upside down in the flange with the threading up when figuring out how to position it. That way, you can see exactly how to position the flange and take the guesswork out of this step.

DIY vs. Hiring a Pro to Fix Toilet Flange Height 

If you have advanced plumbing skills and knowledge, you can purchase a flange extension kit from your local hardware store to fix height issues up to 1 5/8 inches. If your flange height is above that or you’ve never tackled a project like this before, it’s worth calling in a plumber. The average plumber’s hourly rate is between $45 to $200, but talk to your local plumber to get a precise estimate.

If the DIY is done incorrectly, you’re at risk of a wobbly toilet or ongoing toilet leaks. Remember, not all water problems are immediately obvious. Even a toilet that seems to be functioning on the outside could be experiencing more serious issues like drainage problems, sewer gas odors, or damage to surrounding walls and flooring. Hiring a licensed and insured plumber can ensure that your toilet flange height is properly fixed and no other potential damage occurs.