IIBEC Registered Roof Observers (RRO) Practice Test 2025 - Free RRO Practice Questions and Study Guide

The appropriate type of drain for a closed joint waterproofed deck is two-level drains. These drains are specifically designed to effectively manage water drainage in a way that accommodates the waterproofing system used in closed joint applications.

Two-level drains are advantageous because they provide a dual mechanism for water drainage, ensuring that water does not pool on the surface of the deck. The design allows for a more efficient flow of water away from the surface, reducing the risk of leaks or damage to the underlying structures caused by water infiltration.

In contrast, while single channel drains may provide some drainage capability, they might not be as effective in managing the specific flow characteristics needed in a waterproofed system. Multi-level drains may imply a more complicated system that could be unnecessary for this type of application, while inline drains often serve a different purpose and may not adequately address the needs of a closed joint design. The choice of two-level drains aligns well with best practices for maintaining the integrity and performance of waterproofed surfaces.