Question: In reviewing a spec there was a clause “provide a watertight conduit system”. Can GRC be assembled into a “watertight conduit system”?

Answer: The NEC does not recognize any conduit system as watertight, even under normal conditions raceways will collect condensation. NEC Sections 300.5(B) and 300.9 cover raceways in underground and above ground locations. These sections state that these locations are considered “wet locations,” and that conductors and cables installed in the raceways must be suitable for use in wet locations per 310.10(C). Please see question 5 in the FAQs section of this website for more information.