South Carolina Residential Builder Practice Exam 2025 – Complete All-in-One Guide for Exam Mastery!

Sinks must be equipped with waste outlets that are not less than 1-1/2 inches in diameter. This specification is established to ensure adequate drainage and prevent clogging. A larger diameter waste outlet allows for a more efficient flow of water and waste from the sink, reducing the risk of backups and maintaining the plumbing system's overall effectiveness.

In residential construction, adhering to plumbing codes that dictate these dimensions is vital for both functionality and compliance with safety standards. A 1-1/2 inch outlet is the industry standard, commonly used in sink installations, which balances the need for effective drainage without being overly large, which could lead to unnecessary complexities in plumbing layouts.

While other options like 3/4 inch or 1 inch may seem adequate at first glance, they do not provide sufficient capacity for the waste generated in typical sink usage, potentially leading to drainage issues. Additionally, the 3-inch diameter outlet is excessively large for residential sinks, both in terms of space requirements and the potential for decreased pressure in the drainage system. Thus, the choice of a 1-1/2 inch diameter waste outlet is the most practical and widely accepted size for sink installations.