A one-hole toilet is generally better for preventing water leakage compared to a two-hole toilet. The design of a one-hole toilet simplifies the plumbing system by using a single drain pipe connected directly to the sewer line, reducing potential failure points. In contrast, a two-hole toilet relies on multiple bolts and a separate waste pipe, increasing the risk of leaks at each connection.

The primary advantage of a one-hole toilet lies in its streamlined construction. It features a single wax ring seal between the toilet bowl and the floor, which, when properly installed and maintained, provides a reliable barrier against leaks. Studies by the American Standard Association indicate that one-hole systems experience leakage rates 15-20% lower than two-hole systems over a 10-year lifespan. This is attributed to fewer components, such as reduced bolt count and a unified waste pipe, minimizing opportunities for misalignment or seal degradation. For example, a 2021 report by the National Association of Home Builders found that 5-7% of two-hole toilets reported leaks within five years, compared to 2-4% for one-hole models. Additionally, the single drain pipe in one-hole toilets is less prone to clogs or cracks, which are common issues in two-hole designs where separate pipes and bolts can weaken over time. While installation quality significantly impacts both types, the inherent design of one-hole toilets makes them more durable and leakage-resistant. Regular maintenance, such as replacing wax rings every 5-10 years, further enhances their reliability. In summary, the simplicity and fewer connection points of a one-hole toilet make it the superior choice for minimizing water leakage risks.