Bearers must extend a minimum of how many inches over the outside edges of runners?

The correct answer is that bearers must extend a minimum of 3 inches over the outside edges of runners. This requirement is crucial for providing adequate support and stability in various structural setups, ensuring that the weight distribution is effective and reducing the risk of structural failure. By having the bearers extend beyond the runners, it helps maintain a level and secure framework, which is particularly important in HVAC installations where balancing systems and proper airflow are vital. Adequate extension also allows for better insulation and prevents thermal bridging, contributing to energy efficiency. Therefore, the standard of a 3-inch extension serves both safety and performance purposes in construction practices.