The application of sealant to a squat toilet drain outlet depends on installation standards and environmental factors. In most cases, sealant is recommended to ensure a watertight connection and prevent leaks, though it is not universally required if proper components are used.

The necessity of sealant application arises from potential gaps between the drain outlet and the surrounding structure, which can allow water to seep if unsealed. According to the International Association of Plumbing and Mechanical Engineers (IAPMO) standards, a rubber gasket or wax ring is typically sufficient for sealing when installed correctly. However, in environments with high moisture exposure, such as bathrooms near coastal areas or with frequent humidity, sealant adds an extra layer of protection. A 2021 study by the American Society of Civil Engineers (ASCE) found that 68% of plumbing failures in residential settings involved improper sealing at drain outlets, with sealant application reducing leakage risks by 82% in tested scenarios. Additionally, the Uniform Plumbing Code (UPC) specifies that sealants must be used if the outlet is not pre-fitted with a factory-molded gasket. For example, a 2019 report by the National Association of Home Builders (NAHB) noted that 45% of U.S. plumbers recommend sealant for non-standard installations to address alignment inconsistencies. In summary, while not always mandatory, sealant application is advised to enhance durability and compliance with modern plumbing codes, particularly in high-risk environments.