A staffer at my local (generally pretty good) hardware store today told me, with absolute certainty, that code requires that any and all exterior electrical fixtures be installed as follows: conduit run through the wall and sealed at the exterior penetration, with the conduit running into a weather-rated box and the fixture mounted on/in the box with, of course, appropriate weather-rated covers.
He says that the practice that I’ve seen more than once of installing exterior outlets in a box cut into the siding so that it’s flush with the siding, and a weather-rated cover placed over it violates code, for instance.
I am at a loss to understand how most decorative exterior lamps – which I usually see flush-mounted to the siding – could possibly be installed this way.
Am I missing something? Or are all those cut-in outlet boxes and flush-mount carriage lamps on houses around me code violations?
Replies
Not really true...
You can use a pan cake box and install a wet location fixture (luminaire) right to the wall. Some inspectors want to see it caulked in and if it is in a conduit you could say you are required to seal it to prevent condensation.
On the other hand there are millions of these flush mounted luminaires that are simply wired with Romex and they do not get violations from it. If the romex jacket leaves the outside wall, it is a violation.
The only real answer for you will come from your local inspector.
Not true?
410.10 (A)
The fixtures have to be marked for wet location, or if in a damp location must be rated for either damp or wet loactions.
Depending on the type of box used and the weight of the fixture a plastic boxes may not meet the requirements for mounting on a wall. Most metal boxes do, but then you have the requirement fo equipment grounding conductors (bonding or isolation, i.e. double insulation).
Exterior wall mounted boxes are generally passed on the rough-in inspection, and over looked on the final because the inspectors don't consider the weight of a fixture and remeber that they already approved a plastic box for that loaction.
I could find no requirements for sealing the wall penetration by conduite or by type NM cable, but it just make good sense to do so.
300.7 Raceways Exposed to Different Temperatures.
(A) Sealing. Where portions of a cable raceway or sleeve are known to be subjected to different temperatures and where condensation is known to be a problem, as in cold storage areas of buildings or where passing from the interior to the exterior of a building, the raceway or sleeve shall be filled with an approved material to prevent the circulation of warm air to a colder section of the raceway or sleeve. An explosionproof seal shall not be required for this purpose.
That's a good point about using the 3/4" deep 'pancake' box. I had forgotten all about them, and was wondering how I would get a full-depth box between two closely placed studs on an older house.
A 'pancake' box will fit nicely into the siding, and I can anchor it to the sheathing, using a plastic grommet to protect there the Romex enters the box. (Or, better yet, use a box with a cable clamp in it!)
One thing to consider is the placement of the mounts on the light -as compared to the tabs on the box. It does matter which way the box is set in place!