When installing or replacing a toilet, one of the most crucial choices is the seal between the toilet and flange. Traditionally, plumbers have used wax rings for decades, while newer rubber or foam gaskets promise an easier cleanup. We put both to the test in a unique setup that allowed us to apply air pressure and see which seal fails first.
Wax Rings vs. Rubber Gaskets
Wax rings are inexpensive, time-tested, and fit a wide range of flange scenarios. They compress well, creating a watertight (and gas-tight) barrier. Rubber or foam gaskets, however, boast zero mess, reusability, and simpler alignment. They can also maintain shape if the toilet is removed, making them attractive to DIYers.
Real-World Tests
Using a clear acrylic “toilet bottom” bolted onto a test assembly, we installed each ring type, then slowly pumped air. Wax rings held pressure slightly longer before leaking around 25–30 PSI, but eventually gave way. Rubber and foam gaskets often let air escape quickly. While no toilet seal in normal conditions faces such high PSI, the test highlighted each product’s limit under extreme stress.
Which Should You Choose?
In typical home installations, wax rings have a great track record. They stand up well against moderate shifting, temperature changes, and regular use. Rubber or foam gaskets may be appealing if you want less cleanup or plan to remove the toilet often. However, we found wax tends to resist leaks more effectively under high pressure—though none of these products is intended for unusual PSI.
Conclusion
Both wax rings and modern rubber gaskets work under normal conditions. Wax remains the plumbing standard for a reason: it’s reliable, flexible, and widely available. Rubber gaskets have simplicity and less mess going for them. When deciding which to use, consider how frequently you may need to pull the toilet and how often your flooring or flange height changes. In many cases, sticking with wax remains the proven choice.
