Red Seal Plumbing Practice Exam 2025 - Free Red Seal Plumbing Practice Questions and Study Guide

This is because trapping is only necessary for rainwater pipes that are connected to a combined sewer system. A combined sewer system is designed to collect stormwater runoff, domestic sewage, and industrial wastewater in a single pipe system. In this case, trapping is necessary to prevent sewer gases from entering the building through the rainwater pipe. However, if the rainwater pipe is connected to a separate storm drain, there is no need for trapping as the stormwater will not mix with sewage or create sewer gases. Therefore, the statement that trapping is required if the rainwater pipe is connected to a separate storm drain is false.