What is necessary to verify compliance for materials not specifically addressed by the code?

To verify compliance for materials not specifically addressed by the code, providing supporting data including research and testing is essential. This approach ensures that there is credible evidence backing the material's suitability for its intended use. Such supporting data often includes empirical research, laboratory test results, and field studies that demonstrate the material's performance, durability, and safety standards. By having access to this critical information, plumbers and inspectors can make informed decisions regarding the acceptance of alternative materials that may not have been explicitly outlined in existing codes. This process helps maintain rigorous standards in plumbing installations and ensures public safety and environmental integrity.