A reliable toilet seal is critical for preventing leaks from the base of your toilet, but there’s more than one way to make that seal. Traditional wax toilet seals are widely used, but they can be messy and tricky to install. Modern wax-free toilet seals are easier to install, but not always as durable. Professional plumbers use both at times, depending on their preference and job’s requirements. To decide which is best for you, consider the pros and cons of each.

Don’t have a great understanding of the different options for toilet seals? Get started with this video from PEX Universe:

Wax Toilet Seals: Traditional, but Inconvenient

A toilet seal, also known as a tank-to-bowl gasket, forms a semi-flexible seal between the flange (the part in the floor) and the toilet. Traditional toilet seals are made from a ring of wax. Beeswax was the original material, but now vegetable and petroleum waxes are more common. The ring is placed on the bottom of the toilet or the top of the flange. If the top of the flange is below floor level, you’ll need an adapter. Stacking two wax seals is another possible solution, but it’s not ideal. The toilet is placed on top of the flange so that its weight compresses the wax into the exact shape of the flange, forming a perfect seal.

Wax seals are still the go-to for many plumbers. If the flange is particularly high and can’t be lowered, wax might be the only option. Even the thinnest wax-free seal can’t compress as effectively as wax. Other plumbers consider wax seals a cheaper, but messier and outdated option. While wax gets the job done, it’s not easy to work with.

Most wax seals must be above 70 degrees, meaning around room temperature, to be soft enough to mold. Cold wax is too hard to shape and won’t form a good seal. If the wax is too warm, though, the weight of the toilet can squeeze it out of place.

The toilet must be placed exactly over the flange and straight down. Shifting the toilet after you’ve put it down can deform the wax so it doesn’t seal correctly. Lifting and positioning a toilet on your own can be difficult.

If you don’t have another person to help, you might ruin a few seals before you get it right.

Wax seals are highly durable and can easily last 20 years or longer as long as the toilet isn’t moved. The problem with that is that toilets often shift slightly over time. Some new toilet models have smaller bases than older models, making them more likely to rock somewhat when used. Most floors aren’t perfectly level, and while using shims helps compensate, the toilet can still shift. If the floor bolts loosen from corrosion or being bumped once too often, that also allows the toilet to move.

Any of these issues can break the wax seal and let bacteria, mold, and wastewater leak out. There might also come a time when you need to remove the toilet to clear a blockage.

In these situations, you’ll need to remove the old wax seal and install a new one. That requires applying enough indirect heat to soften the wax so that you can scrape it off. It’s a messy job, especially if two wax seals were used.  

Wax-Free Toilet Seals: A Cleaner, Easier Alternative

Most wax-free toilet seals are made from rubber, but you’ll also find models made of soft foam that offer more flexibility than rubber. PVC seals made for deeper flanges are also available. Ease of use is the main benefit of these seals, which makes them a better choice for a DIYer working alone.

Rubber and foam seals are placed over the flange the same way as wax seals. Some can be stacked if necessary. PVC models are typically self-stick and attached to the bottom of the toilet with a strong adhesive. They’re long enough to accommodate flanges below floor level, so you won’t need to stack them.

Once the wax-free seal is in place, just lower the toilet onto the flange, and the ring seals as it compresses. There’s no need to worry about temperature. The material’s flexibility compensates for imperfect placement of the toilet while still forming a perfect seal. You can reposition the toilet several times without needing a new ring as you would with wax. You’ll still need to ensure the toilet is firmly seated. If the seal doesn’t compress enough to let the weight of the toilet rest on the floor, you’ll end up with a wobbly toilet that puts too much weight on the flange.  

These seals’ ability to stand up to heat is another benefit. Although wax seals are usually safe for use in bathrooms with radiant floor heating, using a wax-free seal eliminates the risk of the seal melting. Wax-free seals are also a safer bet in climates with temperatures that reach higher than 100 degrees. At temperatures that high, if your air conditioning goes out, a wax seal can soften enough to leak, but a wax-free seal holds its shape.

If the toilet shifts slightly, a foam seal can change shape to fill any gaps and maintain a seal. Rubber and PVC seals are less able to do this. If you need to remove the toilet, you can reuse the wax-free seal as long as it’s still in good condition. There’s nothing to scrape up or replace. The benefit here is mostly easier clean-up. Toilet seals are cheap, so there’s little cost savings.

Corrosive cleaners such as bleach can damage any type of toilet seal, but rubber and foam seals are more vulnerable. Some wax-free toilet seals come with a 10-year guarantee, but most aren’t expected to last as long as wax models.

The choice between wax toilet seals and wax-free toilet seals ultimately comes down to your personal preference. Many professionals stick with wax because they know it’s reliable, and they’re paid to deal with the mess. If you’re more comfortable with the tried-and-true approach, go with a wax seal. If you’d rather have something that’s easy to install, then a modern, wax-free toilet seal might be a better choice. The best seal for the job also depends on the type of flange you have, so know your toilet before you buy.

Still unsure which option you need? Use the form below to get in touch with local plumbing experts:

Get Free Estimates From Professional Plumbers
Match with a plumbing expert to help you with installation or repair.
Editorial Contributors
avatar for Henry Parker

Henry Parker

Henry Parker is a home improvement enthusiast who loves to share his passion and expertise with others. He writes on a variety of topics, such as painting, flooring, windows, and lawn care, to help homeowners make informed decisions and achieve their desired results. Henry strives to write high quality guides and reviews that are easy to understand and practical to follow. Whether you are looking for the best electric riding lawn mower, the easiest way to remove paint from flooring, or the signs of a bad tile job, Henry has you covered with his insightful and honest articles. Henry lives in Florida with his wife and two kids, and enjoys spending his free time on DIY projects around the house. You can find some of his work on Today’s Homeowner, where he is a regular contributor.

Learn More