Which NEC Section Covers Receptacles Installed in Wet Locations?

The section is 406.9, and the wet location half of it is 406.9(B). It is short, it is specific, and it is one of the most commonly failed items on a residential final because contractors keep installing the wrong cover.

Damp versus wet is the first fork

Section 406.9(A) covers damp locations, meaning places protected from weather and not subject to saturation, such as a covered porch or under a roofed patio where wind driven rain will not reach. There, the enclosure must be weatherproof when the attachment plug is removed. A basic flip lid cover satisfies that.

Section 406.9(B)(1) covers wet locations, meaning anywhere subject to saturation or unprotected weather exposure. The enclosure must be weatherproof whether or not the attachment plug cap is inserted. That is the while in use cover. And since January 1, 2015, outlet box hoods installed in wet locations for 15 and 20 ampere, 125 and 250 volt receptacles must be listed and identified as extra duty. The extra duty marking is stamped on the cover, and an inspector will look for it.

There is one exception worth knowing: a 15 or 20 amp receptacle in a wet location that supplies a single portable tool or appliance not likely to be left unattended may use an enclosure that is weatherproof only when the plug is removed. That covers a landscape lighting transformer or a similar temporary connection, and it is narrow. Do not lean on it for a general purpose exterior receptacle.

The rest of 406.9 that comes with it

Section 406.9(B)(1) also requires that all 15 and 20 amp, 125 and 250 volt nonlocking receptacles in a wet location be a listed weather resistant type. Weather resistant and while in use are two separate requirements and you need both. The receptacle carries a WR marking on the yoke.

Section 406.9(C) prohibits receptacles within or directly over a bathtub or shower stall, with the zone measured 3 feet horizontally and 8 feet vertically from the top of the bathtub rim or shower threshold. Section 406.9(E) requires that receptacles in a wet location not be installed in a face up position on a countertop or work surface unless listed for that use, and 406.5(E) and (F) carry similar face up restrictions for countertops and seating surfaces.

Finally, do not forget 210.8(A)(3), which requires GFCI protection for all 125 volt through 250 volt receptacles installed outdoors in dwelling units, and 210.8(B)(4) for other than dwellings. Wet location construction and GFCI protection are independent requirements. A properly rated extra duty cover on a non GFCI outdoor receptacle still fails.