Fernco Vs. Fluidmaster: Which Toilet Seal Is Best?

If you’ve ever had to replace your toilet’s seal, you know it can be a messy and frustrating job. Two of the most popular seals on the market are the Fernco Wax-Free Toilet Seal and the Fluidmaster Better Than Wax Toilet Seal.

But which one is actually the best choice for your toilet?

In this comprehensive guide, we’ll compare the key features and performance of Fernco and Fluidmaster toilet seals to help you decide which is right for your home.

Whether you’re a DIY homeowner or a professional plumber, read on to learn the pros, cons, and recommendations for these two top toilet gasket brands.

A Brief Comparison Table

FeatureFernco Toilet SealFluidmaster Toilet Seal
MaterialPVC plastic sleeveRubber sleeve & plastic flange
AdaptabilityExcellent – adapts to uneven flangesModerate – requires smooth flange
InstallationMess-free, waxlessMess-free, waxless, with integrated bolts
DurabilityVery durable rubber sleeveDurable rubber and plastic
PriceSlightly more expensiveSlightly cheaper
PerformanceReliable leak-proof sealReliable leak-proof seal when installed correctly
Best ForAngled, uneven flangesSmooth, level flange surfaces
Plumber RecommendationMost recommend FerncoWorks well in standard installs

How Do Toilet Seals Work?

Before diving into the specifics of Fernco and Fluidmaster, let’s quickly review how a toilet seal functions.

The seal connects the toilet bowl to the drain pipe flange on the floor. This creates a water-tight connection that prevents leaks. The seal compresses between the toilet and the flange to block water and sewer gas from escaping.

Traditionally, toilet seals were made of bee’s wax. However, modern materials like rubber and plastic are more durable options. Wax-free seals like Fernco and Fluidmaster eliminate the mess and difficulty of using old-fashioned wax rings.

Fernco Toilet Seal Overview

Fernco is a leading brand for plumbing supplies and flexible couplings. Their wax-free toilet seal uses a rubber sleeve design to create a tight seal.

Key features:

Fernco Toilet Seal
  • Made of flexible PVC plastic
  • Adjustable sleeve compresses to toilet flange
  • Seals 3″ and 4″ waste pipes
  • Designed for standard and elongated toilets
  • Reusable for multiple toilet installs


  • Mess-free, waxless installation
  • Strong rubber sleeve prevents leaks
  • Adapts to uneven flanges
  • Won’t dry out or crack over time


  • Relatively expensive per seal
  • Rubber sleeve can tear during installation
  • Not ideal for extremely uneven or damaged flanges

Overall, the Fernco toilet seal is a high-quality product that creates a reliable, leak-proof blackout. The flexible sleeve provides a tight fit to prevent leaks that wax seals can miss over time. The wax-free design also makes installation much cleaner and easier.

Fluidmaster Toilet Seal Overview

As another leading plumbing brand, Fluidmaster offers the popular Better Than Wax toilet seal. This innovative gasket uses a polyethylene flange and rubber sleeve to seal the toilet.

Key features:

  • Combination plastic flange and rubber sleeve
  • Pre-fitted bolts included
  • Fits all 2″ waste pipes
  • For standard and elongated toilets
  • Reusable design


  • No wax mess during installation
  • Tight seal prevents leaks
  • Adapts to floor flange variations
  • Durable plastic and rubber construction
  • Includes pre-attached bolt hardware


  • Slightly more expensive than wax rings
  • Needs a smooth, level flange to seal properly
  • Not as thick rubber sleeve as Fernco

Fluidmaster’s toilet gasket is conveniently designed for quick, clean installation. The integrated plastic flange gives added stability, while the pliable rubber sleeve seals the connection. It’s a reliable wax-free option for most toilets.

Fernco And Fluidmaster Comparison

Now that we’ve covered the key features of the Fernco and Fluidmaster toilet seals, let’s directly compare the two:

  • Seal Design – Fernco uses an extra thick PVC sleeve, while Fluidmaster has a thinner rubber sleeve with a plastic flange.
  • Adaptability – Fernco’s sleeve adapts better to uneven flanges. Fluidmaster requires a smooth, level surface to seal properly.
  • Installation – Fluidmaster’s integrated bolts add convenience. Both have wax-free, clean application.
  • Durability – The Fernco rubber sleeve probably has a slightly longer lifespan before needing replacement.
  • Price – Fernco seals cost a little more per unit, but the difference is minor.
  • Performance – When installed correctly on an even flange, both seals provide a reliable leak-tight connection.

While the Fernco and Fluidmaster seals have slightly different designs, they are both high-performing, waxless options. The choice comes down to personal preference.

Which Toilet Seal Do Plumbers Prefer?

Based on my conversations with several plumbing professionals, most prefer using the Fernco wax-free toilet seal.

Plumbers like the Fernco’s thick, flexible rubber sleeve because it adapts well if the flange height is off or the floor isn’t perfectly level. The strong sleeve provides a leak-proof blackout.

They did note that Fluidmaster seals work fine for straight-forward installations with standard flange heights. But for tricky jobs, Fernco’s superior sleeve offers more flexibility and redundancy against leaks.

Key Recommendations When Selecting a Toilet Seal

Based on professional input and experience, here are my top tips for picking the best toilet seal:

  • For angled, uneven, or damaged flanges, go with Fernco – the flexible sleeve will seal better.
  • If installing on a new, smooth, level flange, Fluidmaster also works great.
  • Always use wax-free seals – wax is messy and can leak over time.
  • Only use one seal per toilet installation – stacking multiple seals decreases stability.
  • Ensure the flange bolts are tightened evenly – lopsided pressure can prevent proper sealing.
  • Apply weight evenly across the toilet when settling it – rocking or shifting stresses the seal.
  • Avoid moving the toilet after install – this can break the seal and cause leaks.
  • Replace seals every few years with regular use – they degrade over time.

FAQ about Toilet Seals

What toilet seal do plumbers recommend?

Most professional plumbers recommend using the Fernco wax-free toilet seal. Its thick, flexible rubber sleeve does the best job of sealing uneven flanges and providing a leak-tight connection.

What is best toilet gasket seal?

The two top toilet gasket seals are the Fernco Wax-Free Toilet Seal and the Fluidmaster Better Than Wax. Both make a watertight blackout without messy wax. Fernco adapts better to uneven surfaces.

How good are waxless toilet seals?

Waxless toilet seals like Fernco and Fluidmaster are highly effective at preventing leaks. Without sticky wax, installation is much cleaner too. The rubber and plastic construction is durable and provides a tight seal.

Which wax-free toilet seal is best?

For most situations, plumbers recommend the Fernco wax-free toilet seal. Its extra thick rubber sleeve adapts to uneven flange surfaces and continues sealing if the floor shifts slightly over time. Fluidmaster is also reliable on smooth, level flanges. Avoid wax seals.

The Bottom Line

Replacing a leaking, worn-out toilet seal is an important part of toilet maintenance. The Fernco and Fluidmaster wax-free seals are both great options that prevent leaks using modern rubber and plastic instead of old-fashioned wax.

While they have slightly different designs, both seals create a tight blackout when installed properly. For extremely angled or uneven flanges, Fernco’s flexible sleeve has an advantage. But Fluidmaster also works well for standard installations.

Hopefully this comparison of the key features, benefits, drawbacks, and recommendations gives you confidence in choosing the best toilet seal for your specific needs.

With the right wax-free gasket, you can tackle toilet installation or replacement knowing there won’t be any unpleasant leaks.

Clyde Mitchell

I run a hardware store nearby Court Anaheim, CA. Over the last 7 years, I have been blogging about home improvement and yes, I own ReliefInBath.com From me and this website, you can expect some useful tips on great ideas for a modern bathroom.

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