Many electrical contractors, electricians and electrical inspectors have struggled with the requirements in the National Electrical Code (NEC) for placement of lights, receptacles and switches in bathtub and shower areas. Can receptacles be installed within proximity of the bathtub or shower edge? Are luminaires installed in or near these areas required to be listed for wet, damp or dry locations? Is it permissible to locate a switch in this area? The 2005 NEC has been revised to address these issues.
Where dealing with a shower or a tub location, one of the biggest installation problems has been determining if a luminaire will be subjected to condensation or water intrusion. Will a shower head cause water to enter the luminaire, thereby shorting it out or causing an electrocution? What effect will condensation have on the luminaire? Will mist or steam penetrate its energized parts?
Section 410.4(D) has been revised for the 2005 NEC to more clearly address these problems and provides some relief in designing, installing and inspecting these areas. Adding a single sentence at the end of this section provides clarity where dealing with the location and type of luminaire for a shower or bathtub location.
The added text is as follows: “Luminaires (lighting fixtures) located in this zone shall be listed for damp locations, or listed for wet locations where subject to shower spray.”
The only problem with this particular change in the 2005 NEC involves the term “zone,” as used in this new last sentence. Zone is the area measured three feet horizontally and eight feet vertically from the top of the bathtub rim or shower stall threshold.
In small bathrooms, measuring three feet horizontally from the edge of the bathtub rim or shower stall threshold can often include wall-mounted luminaires located directly above an adjacent sink. Since most bathrooms are drywall or Sheetrock with a textured coat of drywall mud and paint, any excessive moisture in the bathroom would cause deterioration of the wall surface long before moisture would affect luminaires mounted in the zone but outside the actual “footprint” of the bathtub or shower. Consult with the electrical inspector for an interpretation on this issue.
This new requirement was inserted into the 2005 NEC primarily to cover wall-mounted wall sconce luminaires, but this section also covers recess, as well as ceiling mounted, luminaires mounted directly above this zone.
A wall-mounted luminaire in this zone must be listed for a damp or wet location, depending on the application. Recess incandescent luminaires can be provided with a trim that makes the recess can and trim suitable for a damp or wet location.
Luminaires mounted above the eight-foot area covered by the zone are clearly not affected by mist, steam or direct spray. A decision by the authority having jurisdiction and the installer must be made in addressing whether a luminaire will be in the direct spray of the shower head itself, but even this should be fairly evident based on the type of construction used in this specific area. If the wall is built of water-resistant material of any kind, then the luminaire should be a wet-location luminaire since the installer is anticipating excessive moisture.
Receptacles installed in a wet or damp location must comply with Section 408.8 dealing with wet or damp locations. Section 408.8(D) within this section does not permit receptacles to be installed within or directly over a bathtub or shower stall. Rather than referring to the bathtub or shower zone, as was done for luminaires, this section addresses the footprint of the bathtub or shower stall.
Receptacles installed adjacent to a bathtub or a shower stall would not be a violation of this section. For example, garden atriums located adjacent to bathtubs and showers are common in some larger homes, hotels and similar structures. Receptacles are often added in these small garden areas to supply fountains, waterfalls and lighting.
Some garden atriums even have sprinkler systems installed for the plants. These receptacles are clearly in a wet or damp location, even though not located within or over the bathtub or shower area and, therefore, must have an enclosure and cover that is weatherproof with the attachment plug inserted or removed or, in other words, a weatherproof box with a bubble cover.
Similar to receptacles, switches installed in these areas are required to comply with Section 404.4’s last sentence that states as follows: “Switches shall not be installed within wet locations in tub or shower spaces, unless installed as part of a listed tub or shower assembly.”
As designers and installers of bathtub and shower areas continue to create new and dynamic designs for bathrooms, the NEC will continue to apply necessary safety requirements for these areas. EC
ODE is a staff engineering associate at Underwriters Laboratories Inc., in Research Triangle Park, N.C. He can be reached at 919.549.1726 or at email@example.com.