Interpretation #: CEB-2018-05-2005-IRC-TE3704.1

Building or Fire Safety Law Interpreted

675 IAC 14-4.3, the 2005 Indiana Residential Code, Table E3704.1 which states NM (non-metallic) cable may not be used in "wet locations exposed to sunlight", nor in "damp locations".

Interpretation of the State Building Commissioner

Table E3704.1 of the IRC provides restrictions on the acceptable applications, locations, and exposures of various wiring types. It does not address electrical devices or fixtures based on exposure, nor does it tie the allowable wiring types to the wet/damp/dry status of the device or fixture being served. In other words, the Table is based on the exposure of the wiring itself and nothing more. In this instance, the petitioner is providing power to devices and/or fixtures that are located in wet, sunlit and/or damp locations, but the wiring itself is not exposed. The code official is citing the Table's prohibition on NM cable for these locations due to the exposure of the device and/or fixture, maintaining that devices in such those locations require the use of wiring other than the petitioner's NM cable. However, as stated above, the Table refers to the exposure of the wiring itself, and not the devices it feeds. If the wiring itself is exposed to water, sunlight or dampness, or the raceway that contains it is similarly exposed or subject to water leaks, then NM cable may not be used. If not, then the Table's wet/damp restrictions on NM cable do not apply. It is up to the compliance and weather-resistance of the construction materials around exterior devices and fixtures (and the quality of workmanship in their installation) to protect the wiring, along with every other building component that is potentially at risk in these areas.