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Bathtub Drain Flange Sizes: How To Measure and When To Replace

Are you having trouble with a clogged drain and need to replace your bathtub drain flange? If you’re having trouble figuring out the right size of your bathtub drain flange, you’ve come to the right place!  Read on to learn about the different sizes and how to measure yours for a replacement.

Bathtub Drain Flange

Bathtub Drain Flange Sizes

The standard bathtub drain flange sizes are 4-inch, 6-inch, 8-inch, and 10-inch, but you can find custom sizes too. 

If you notice your flange is damaged, it’s time for you to replace it!

What Is a Bathtub Drain Flange?

Bathtub drain flanges prevent clogs and discharge water into the sink or bathtub. We use them when drain pipes become blocked with hair, soap pieces, dirt, and other materials. 

A bathtub drain flange is a large metal piece that sits on top of the bathtub and connects to the drainpipe. 

These flanges keep water from leaking out of the tub when it’s turned off or low on water. They also connect to your tub and the nearest wall in your bathroom. 

Why You Need a New Bathtub Drain Flange 

Clogged bathtub drains can cause flange problems. Debris buildup in the drainage system can lead to bigger plumbing issues for you, like the ones below. 

Bathroom Drainage Problems – When bathroom draining issues arise, water gets trapped. It can’t travel through and accumulates inside the sink basin. 

Flooding or Sewage Backup in Your Bathroom – This accumulation can lead to flooding and sewage backup in your bathroom. Besides blocked bathtub drains, other causes of bathroom drainage problems include defective waste disposal systems or faulty toilet connections. 

Cracked Bathtub Drain Flange – There are a few things you can do to fix a cracked bathtub drain flange. The first is to try using some of the DIY solutions that are available online, such as using a plumber’s putty or epoxy.

However, I suggest you don’t waste your time. Instead, I find it’s better to just replace the flange outright.

What Sizes Do Bath Tub Drain Flanges Come In?

Standard bathtub flanges come in 4-inch, 6-inch, 8-inch, and 10-inch sizes. Of course, you can get smaller or larger flanges custom-made.  

Custom varieties are available for people who have odd-shaped bathrooms. 

How to Measure Bathtub Drain Flange Sizes 

Choosing the right bathtub drain flange involves taking a few measurements of your bathtub. For example, a Jacuzzi tub will have different size requirements than a smaller tub. Here’s the best way I know to measure a flange:

  1. To measure a bathtub drain flange, you will need to unscrew and remove the old one. 
  2. Next, you will need to locate the bathtub drain pipe coming out of the wall studs. 
  3. Using a level, mark the location of the pip top against the wall studs. 
  4. Unscrew and remove the new flange from its packaging (it should come in two pieces). 
  5. Place one piece over the top of the marked location on the wall studs, screw it into place using your wrench/cable tool, and tighten with your other hand. 
  6. Use your tape measure to make sure that both ends are at equal distances from each other. 

Ensure the flange is compatible with your plumbing system and drains before you install it. 

Bathtub Flange

Where to Buy a New Bathtub Drain Flange

Find the best bathtub drain flanges brands at competitive prices by shopping local hardware stores or calling a reliable plumber. 

Be sure to read customer reviews before purchasing to understand what people liked and didn’t like about different models. 

Finally, always use caution when installing any type of drain flange — never put one in without first checking it against the manufacturer’s instructions! 

Important Notes About Bathtub Flange Sizes

When choosing the right size for your flange, you need to account for the depth and diameter of your tub. 

You can determine the depth by how deep the drain pipe goes into the ground, while the diameter refers to how wide your opening will be. A flange that’s two inches larger in diameter than your drainage will work best. 

How Do You Clean a Bathtub Drain Flange?

You may need to clean the flange if it becomes blocked by excessive buildup. There are a few ways you can clean a bathtub drain flange. One way is to use a plunger. 

Put the plunger over the drain and push and pull it up and down until the clog falls out. If the clog is hard, you can try using a snake toilet cleaner or cleaning liquid coupled with hot water.

Is It Time To Replace Your Bathtub Drain Flange?

You should probably replace a bathtub drain flange every 10 to 12 years. I always suggest you give a thorough inspection or get a replacement as needed after such events as leaking, rusted screws, corroded joints, or damage from excess water pressure

How To Replace a Bathtub Drain Flange

Unfortunately, your best option may be to replace the drain flange. If so, follow these steps:

Step #1. – Remove the old drain by unscrewing the screws that hold it. Use pliers to turn the hexagonal head of the screwdriver so that it can get a grip on one side of the nut at either end and twist until it comes off. Save these screws for later if you need them.

Step #2. – If there is an overflow tube connected to the tub drain, detach this by gently pulling up on one edge and then twisting it slightly away from the main body of the pipe – be careful not to damage it in any way (it may have a metal


Replacing Bathtub Drain Flange

Step #3. – Remove shower heads attached to the tub drainpipe by unscrewing it by turning it about a quarter turn. Turn the screw counter-clockwise for threaded pipes. Keep track of all pieces that came off during the removal process. 

Step #4. – Carefully remove the soapy water and grime from around both pipes using a plunger or garden hose. Don’t use excessive force to soap up your work area and dislodge debris.

Frequently Asked Questions

Still have questions about bathtub flanges? I’ve got you covered.

What is a bathtub drain flange?

A bathtub drain flange is the part of the sink or lavatory that attaches to the sewer line and allows wastewater to flow out of the system.

Who can install a bathroom drain flange?

A plumber can install a bathroom drain flange and provide household plumbing services like fixing a leaky faucet, unclogging a sink, or installing pipes for a new water heater or dishwasher. 

Of course, if you’re DIY-inclined like me, you’ll be able to install your own flange!

Is a bathtub drain flange hard to fix?

A malfunctioning bathtub drain flange caused by a clogged drain can be tricky to fix. Replace cracked or broken flanges instead of trying to repair them. It may seem more troublesome, but trust me. It’ll be faster in the long run.

Where can I buy a new bathtub drain flange? 

Some bathtub drain flange retailers include Home Depot, Lowes, Menard’s, and Ace Hardware. You can also order a new bathtub drain flange online or directly from your local plumber.

What sizes do bathtub drain flanges come in?

Drain flanges come in different sizes, based on the size of your bathtub. They can vary in diameter from 1/2 inch to 3 inches and length from 3-inches to 12-Inches.

What are the different bathtub drain flanges?

1. – Threaded flange: this type has threads on the top and bottom of the flange for secure installation.

2. – Self-cleaning flange: this type features a built-in filter that helps to clean the drain after use.

Bathtub Drain Flange Replacement Near Me

Bathtub flanges have become increasingly popular in recent years as they allow for a more custom fit when installing your new shower or bathtub.

The benefit of using a bathtub drain flange is that it can help prevent clogged drains. A new bathtub drain flange can also improve water flow and drainage in your bathroom.

Call a licensed plumber If you have questions about cleaning or replacing your bathtub drain flange.

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