I've recently had a kitchen renovation done - actually swapping the kitchen and dining rooms. The electricians were subs working for the company doing the reno.

They ran some new circuits for the recessed and hanging lights, but also wired some of that up to wiring that existed for the old dining room, which also had recessed lighting.

They tied some of the wiring together in the attic. In most places, they put the connections in a junction box (I corrected one or places where connections (wire nuts) were just dangling in the air). But, in all cases the junction boxes are not covered and are not fastened to anything. They were just left lying on the insulation. Here's a couple of pictures of what I found:

This first one shows where they used one of old recessed light fixture to join tie so wiring together. I cut off the gooseneck to the light fixture itself.

enter image description here

This next picture shows a 3-gang box being used to connect another group of cables together. I have no idea why they would foam the box penetrations but leave off a cover.

enter image description here

So basically two related questions.

  1. Should these boxes have covers on them?
  2. Should they be be fastened to a joist, rafter, or some other structural member?

Edit 1 - Replaced plastic box

I took the advice here and replaced the plastic 3-gang box with a 4"x4" metal box, using appropriate through-the-box cable clamps. I will post a picture of the final product.

Mar 14

Here's the promised picture, before the cover went on.

enter image description here

  • 4
    Worse, the spray foam is highly flammable (bordering on napalm), and as such, illegal in junction boxes. Nov 20, 2022 at 22:18
  • 4
    Ugh. Definitely should have covers. And really no reason for plastic boxes loose in the attic. I understand the rationale for the plastic boxes when fitting into existing walls (though metal is still better) but loose? That's crazy. Metal boxes aren't very expensive and the covers are easy, and especially can't be beat for fire (arc, etc.) safety. But I'll let someone who can cite code answer as far as covers, etc. Nov 20, 2022 at 22:27
  • 5
    Contact the licensing board in your LAHJ. Which licensing board would depend if the General contractor hired unlicensed electricians illegally, or if supposedly licensed electricians did this work. Of course, your LAHJ's inspectors are not looking great at the moment, either, if there are any. This is not even up to "shoddy" it's downright criminal incompetence.
    – Ecnerwal
    Nov 20, 2022 at 23:04
  • 2
    Why covering the boxes ? A nail or screw can fall in it, and create fireworks.
    – Traveler
    Nov 21, 2022 at 0:47
  • 3
    That is truly top tier $hit work.
    – MonkeyZeus
    Nov 21, 2022 at 13:29

1 Answer 1


When cutting off wires coming out of a junction box, you must go into the box and remove the wires from their wire nut splices. Otherwise the cut off wire ends will be energized (and 1/8" apart, what could go wrong? LOL)

The large blue box is improper for 3 reasons: the two you cited and also the use of "spray foam" to seal box openings. Canned spray foam is highly flammable to bordering napalm. Claims of its fire resistance are grossly overstated, as proven time and time again. Check out this vid, particularly what happens at 12:56.

I would replace it with a common steel box with knockouts, using proper 3/8" cable clamps in the holes in the knockouts. The little nub is for a #10-32 screw; attach a 6" long bare ground wire and tie it to all the cable grounds. Then any blank cover. Attach the steel box to the studs somewhere using either the provided holes, or holes you drill. Don't drill holes into knockouts.

The neat thing about a steel box is if a wire comes loose and touches the box shell, BLAM the breaker trips. If overheating occurs in wire terminals, the steel box carries heat well and will carry heat away to reduce hotspots that might ignite materials.

The other feature of metal boxes is they're designed to be used with blank covers, which are readily available. Plastic boxes are designed to have sockets and switches in them, and blank covers are oddities. That's why the last guy didn't use one: hard to find.

  • 1
    The wires coming out of the metal box that was part of a recessed light housing through the goose neck had already been removed back to the wire nuts. I just cut off the now empty goose neck. So no cut off or otherwise bare wire ends that I can tell.
    – SteveSh
    Nov 20, 2022 at 22:55
  • Last paragraph misses that the metal box didn't have a cover either! Nov 20, 2022 at 23:16
  • On the metal box, I was able to find a cover from a discarded/spare recessed light fixture I had and so was able to easily close off that open box,
    – SteveSh
    Nov 21, 2022 at 1:39
  • 1
    @MonkeyZeus Yes, plastic clones of corner-screw 4x4 boxes exist, but only at the most well-stocked large stores and at 2-3x the price of a bog standard metal box. They seem to be some sort of specialty niche. Whereas any hardware store will have all the steel box kit - boxes, mud rings, domed covers. As such I consider them irrelevant. Nov 21, 2022 at 20:04
  • 2
    If you have a need for a blank cover and have a hard time finding one in a particular size for some reason, there are blank Decora inserts available.
    – Ecnerwal
    Nov 23, 2022 at 13:57

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