Types of Toilet Flanges Explained in Detail

Choosing the right toilet flange is critical for proper toilet installation and performance. Toilet flanges connect the toilet to the drainpipe, securing the toilet in place and creating a tight seal to prevent leaks and odors. With several types available, it's important to understand the key differences to select the optimal flange.

Cast Iron Flanges

Cast iron flanges provide maximum strength and durability for connecting toilets to cast iron drain pipes. The heavyweight cast iron material resists corrosion and abrasion even after years of use.

Bell-Type Cast Iron Flanges

The bell-type cast iron flange is the most common style. It features a bell-shaped opening with a curved lip that fits over a cast iron drainpipe. The bottom extends 3-4 inches into the pipe for increased stability. Corrosion-resistant bolts secure the flange over the drainpipe. A wax seal ring fits between the flange and toilet to prevent leaks.

Bell-type cast iron flanges accommodate minor misalignments in the drainpipe position. The extended lip and bell design allow pivoting the flange slightly during installation to line it up perfectly. This versatility makes it easy to create a secure, leak-free connection.

Threaded Cast Iron Flanges

Threaded cast iron flanges have female threads on the bottom that screw directly onto male threaded cast iron drain pipes. Applying thread sealant or pipe joint compound ensures a tight seal. An additional wax ring seals the connection to the toilet. Threaded flanges provide a very secure connection but allow for toilet removal if needed.

The threaded design offers less pivoting ability compared to the bell-type. Careful drainpipe alignment is important during installation. Overall, threaded cast iron flanges offer a durable, long-lasting toilet connection.

PVC Flanges

PVC flanges provide an affordable, corrosion-resistant option for connecting toilets to PVC drain pipes. The PVC plastic material withstands exposure to moisture, chemicals, and abrasion. PVC flanges are about half the weight of cast iron, making them easier to handle.

Glue-On PVC Flanges

Glue-on PVC flanges feature a smooth socket on the bottom that slides directly over a PVC drainpipe. PVC cement permanently bonds the flange to the pipe for maximum strength and a permanent leak-free connection. The glue-on style is quick and easy to install but does not allow toilet removal without cutting the drainpipe.

Glue-on PVC flanges are the most popular style due to the simple installation. Proper solvent welding procedure is critical, however, to ensure a sound joint. The drainpipe must be straightened, chamfered, and cleaned before applying cement primer and adhesive.

Threaded PVC Flanges

Threaded PVC flanges have female threads on the bottom to screw onto male threaded PVC drain pipes. Applying thread sealant tape prevents leaks at the threads. The threaded connection allows easier toilet removal without cutting the drainpipe. However, the joint may be more prone to loosening over time.

Threaded PVC flanges should be tightened by hand only to avoid cracking the plastic. Completely wrapping the threads with at least 3 layers of sealant tape prevents water infiltration and sewer gas odors.

ABS Flanges

ABS plastic flanges offer similar advantages as PVC but with maximum durability and impact resistance. The ABS material withstands physical abuse, temperature extremes, and chemical exposure better than standard PVC. Most ABS flanges feature a glue-on socket design for creating a permanent, water-tight joint.

Stainless Steel Flanges

Stainless steel flanges provide unmatched corrosion resistance and durability for demanding commercial applications. The rugged stainless steel material will not rust or corrode even after decades of use and exposure to water, chemicals, and physical impacts.

Most stainless steel flanges combine a plastic bottom socket that glues onto standard drainpipes, along with a stainless steel top ring that provides the bolting surface. This hybrid design offers corrosion resistance where needed combined with standard plastic pipe connections.

All stainless steel closets flanges are also available. The all-stainless construction allows fabrication of any custom flange size and bolting configuration.

Closet Flanges

Closet flanges, also called floor flanges, provide the mounting surface to secure the toilet to the floor. The closet flange is separate from the drainpipe connection flange. PVC and ABS are common closet flange materials due to their corrosion resistance and durability.

Closet flanges use corrosion-resistant bolts to bolt the toilet in place. Nuts get tightened on the threaded bolts with a proper torque wrench to ensure a secure installation without cracking the flange. Rubber or neoprene washers prevent water from infiltrating at the bolt holes.

Offset closet flanges shift the bolt pattern to one side to allow installing the toilet over drainpipes not precisely centered behind the toilet. Offset closet flanges are vital for flexibly dealing with small drainpipe positioning inconsistencies.

Repair Flanges

Repair flanges provide an easy way to fix or replace broken, leaky, or deteriorated flanges without removing the drainpipe. These flanges fit over an existing flange, securing in place with bolts. Having the correct repair flange size is critical for proper installation.

Repair flanges come in ABS, PVC, and stainless steel material options to match most flange types. Stainless steel repair flanges offer extreme corrosion resistance for long life. PVC and ABS repair flanges provide budget-friendly solutions.

Inspect the condition of the old flange closely before installing a repair flange. Check for severe corrosion or damage that would require complete replacement. Also confirm the original flange size and offset to select the proper repair flange.

Key Factors in Choosing Toilet Flanges

Consider the following critical factors when selecting toilet flanges:

• Drainpipe material - Match the flange to the existing drainpipe material.
• Installation method - Choose threaded or glue-on styles based on application.
• Offset need - Determine if an offset flange is required.
• Drainpipe size - Confirm dimensions to get the proper flange size.
• Fixture load - Select a rugged flange for heavy commercial use.
• Water exposure - Choose corrosion-resistant materials if needed.
• Sealing method - Consider wax ring vs. gasket options.

Additionally, ask licensed plumbers about the optimal flange type for your specific residential or commercial bathroom installation needs. Doing upfront research prevents toilet connection problems down the road.

Common Toilet Flange Issues

Some common toilet flange problems include:

• Loose, wobbly toilet - Indicates deteriorated or broken closet flange bolts.
• Rocking toilet base - Often caused by a damaged or aged wax ring seal.
• Visible water leaks - Leaky wax ring or defects in the flange seal.
• Sewer odors - Cracked flange or loose drainpipe connection.
• Toilet clogs easily - Could indicate a misaligned or offset flange.

Catching flange issues early allows for quick repairs. But delaying too long may require full flange replacement. Annual inspections help spot problems before major toilet or flooring damage occurs.