For IMC metallic ducts installed in/under concrete, which option is not a required compliance?

For IMC metallic ducts installed in/under concrete, which option is not a required compliance?

• A. Encased on all sides with minimum of 2 inches concrete
• B. Properly secured before pouring concrete
• C. Sloped to an excessive plenum for drainage
• D. Accessible for cleaning

Answer: (D)

When ducts are installed in or under concrete, the emphasis is on protecting the duct, keeping it in place, and managing moisture, not on accessibility for routine cleaning. The duct must be encased on all sides with a minimum of two inches of concrete to shield it from damage and to provide a stable, continuous barrier. It also must be properly secured before pouring the concrete so it doesn’t shift or create gaps during placement. Sloping the duct toward a drainage path helps prevent condensate or moisture from pooling inside the duct, reducing the risk of corrosion or blockages. Accessibility for cleaning isn’t required in this scenario because buried ducts aren’t practically reachable for cleaning after installation; any needed maintenance would be addressed by access cuts or design considerations, not by a cleaning-access requirement.

When ducts are installed in or under concrete, the emphasis is on protecting the duct, keeping it in place, and managing moisture, not on accessibility for routine cleaning. The duct must be encased on all sides with a minimum of two inches of concrete to shield it from damage and to provide a stable, continuous barrier. It also must be properly secured before pouring the concrete so it doesn’t shift or create gaps during placement. Sloping the duct toward a drainage path helps prevent condensate or moisture from pooling inside the duct, reducing the risk of corrosion or blockages. Accessibility for cleaning isn’t required in this scenario because buried ducts aren’t practically reachable for cleaning after installation; any needed maintenance would be addressed by access cuts or design considerations, not by a cleaning-access requirement.