A Guide to Toilet Flange Types

Today’s market offers a variety of flange types, based on material composition. Among some of the options are PVC, ABS, cast iron, brass or materials based on specific application needs.

The choice of toilet flange depends on the material of the DWV pipe it is being connected to. That means, if you have a PVC pipe connection, you should install a PVC closet flange. A cast iron connection will require a cast iron toilet flange, and so forth.

It’s helpful to know the different types, sizes and features when you need to repair or replace a damaged flange. But before we jump into the various options, let's first discuss the function of a toilet flange.

What is a toilet flange?

A toilet flange, also called a closet flange, is a pipe fitting that connects a toilet to the drainage system while also securing it to the finished floor. A toilet flange securely attaches a toilet to the home's drainage system through an approved connection method. The flange is also anchored to the subfloor with a rust-proof screw keeping it stable and free from movement.

We don't recommend using drywall screws. That’s because they will deteriorate over time if they come in contact with water. At that point, movement can occur and the toilet flange can become damaged and connection to the pipe can become compromised.

A wax ring, mounted on the closet flange, creates a watertight seal between the bottom of the toilet and the closet flange, preventing any leaks, odors or sewer gases from escaping the fixture. T bolts, or as Oatey calls them, "Johni-Bolts," are used to connect the toilet (via slots) to the toilet flange.

Before you head to your local supply house or nearest hardware store to purchase a toilet flange, let's explore the different types to ensure you choose the correct toilet flange for your particular application.

Types of flanges

As mentioned earlier, keep in mind that the choice of toilet flange depends on the material of the pipe and connection method.

1. PVC or ABS Toilet Flanges

The Oatey® Level Fit Closet Flange is a good choice when you are simply changing out the flange. The PVC toilet flange (or ABS) quickly and easily connects water closet outlets to a plumbing system and sits flush on the finished floor surface.

The test cap is designed to break out cleanly and easily, eliminating the possibility of falling down the drain. The Level Fit is available with a stainless steel, metal, or plastic ring. It can be installed over 3" Schedule 40 DWV pipe, inside 4" Schedule 40 DWV pipe or over 4" Schedule 40 DWV pipe.

Oatey® Easy Tap® Closet Flanges are a good choice for PVC or ABS applications. They are available in various materials and styles, with a test cap that easily and cleanly breaks out, also eliminating the possibility of falling down the drain. Available with a stainless steel, metal, or plastic ring, Oatey Easy Tap fits over 3" pipe or inside 4” pipe.

The use of a closet flange with a knockout plug will depend on the application. So, if you are installing a new plumbing system that requires testing, or remodeling a bathroom and would like to keep sewer gases from escaping, Easy Tap is a good option.

2. Cast Iron Toilet Flanges

Oatey® Cast Iron Closet Flanges are designed for use on plastic pipe or heavyweight, service weight or no hub cast iron soil pipe. The installation does not require caulking, and it comes complete with the body, brass ring, bolts, and gasket. These flanges install on the outside of either 3" or 4" pipe.

The 4" Cast Iron Twist-N-Set® Replacement Closet Flange is a good option for broken cast iron flanges needing replacement. The Twist-N-Set Replacement Closet Flange is designed to replace broken cast iron closet flanges with a gasket that expands to fit inside of heavyweight, service weight, and no hub pipe.

3. Brass Toilet Flanges

Some older homes may still have a lead bend in place, relying on the use of a brass closet flange. This connection should be performed by a skilled tradesperson, because it requires a more traditional connection method.

When the connection is made, the lead is peened to the inside of the closet flange and the two materials are joined together with solder. Most of the time, when repairing a brass flange, the lead material may have deteriorated beyond repair. If this is the case, the old lead bend will have to be replaced.

The Oatey® 3" or 4" Brass Closet Flange Replacement Ring is available for brass applications. It has three countersunk holes and three closet bolt slots for a secure attachment to the floor.

4. Specialty Options

  • 45-Degree Closet Flanges: The Oatey® ABS or PVC 45-Degree Closet Flange with a Stainless Steel Ring is designed for applications in which clearance doesn't allow for normal flange installation.

The hub comes off the bottom of the closet flange at a 45-degree angle. This is helpful if there is an obstruction underneath or if you need clearance where an application doesn't allow direct attachment vertically into the closet flange. The 3" or 4" Level Fit 45 degree closet flange allows for solvent welds over 3" or inside 4" Schedule 40 DWV pipe.

  • Offset Closet Flanges: Used for PVC or ABS applications, the Oatey® Level Fit Offset Closet Flange can be rotated for precise alignment of bolts and screws. The rings provide flexibility with a 360-degree swivel.

So if there are floor joists that prevent the closest flange from being centered during installation, the Level Fit Offset Closet Flange offsets the hub of the closet flange around that obstacle. That way, you can still install the toilet where it needs to go. This flange is available with a stainless steel or metal ring.

Now that we have explored the different types of toilet flanges, you can choose the correct toilet flange for your particular application. Not sure how to repair a toilet flange? Check out this blog for step-by-step instructions.

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