Hi there,Al, It makes me wonder why these boxes are missing their covers in the first place. You say you are in Chicago, the land of EMT, this whole system needs to be closed to prevent the spread of fire. Is there a problem with box-fill that covers can't be fitted? Either way, I have a problem with covering any sort of junction box with insulation. Maybe Greg or someone closer to you, could give some direction on this.
I note in your profile you are a teacher, is that in Electrical Tutor? Please note that we don't field questions of the DIY nature here, if you don't hold electrical qualifications, please seek the services of someone that does.
I found that when I moved into my house and it is a typical indication of unpermitted uninspected work.
I would strongly suggest getting a licensed electrician to look this over to be sure missing covers is the only danger. I found splices that were just twisted and taped and a witches brew of other dangerous violations. At a bare minimum you should put covers on them. It is normal to bury them in insulation but it is certainly a pain when you have to find them again. Take a sharpie pen and write a location mark over each one on the truss chord or rafter above it with the type of box and where it is. Note the ones that look like "add on" work. You will thank yourself later.
Anyway, the house was built in 1919 and the electric was updated with all the old knob and tube being removed. It was all done by a professional as there was a sticker from the company on the service box and they had a record of the work. I had the work inspected by an separate electrician in addition to the "normal" inspector for the house before I bought and the electrician was pleased with the work. His statement was that I should upgrade my service from a 100A to 200A (due to some plans I had) and put covers on the boxes in the attic but I didn't ask about laying insulation over them after that.
Thanks for the tip about marking where they are with a sharpie. I will try to avoid them all together but in case I cannot for some reason, I will mark them.
You can insulate over the closed boxes eslewhere in the US, I don't know if Chicago has other requirements. The sharpie is a wonderful idea. I wish I had done such back when I did my own home. Just to find a luminaire device box in an attic where all looks the same and you have just a general idea of location? Sometimes the people here are beyond brilliant.
I for one welcome you here and commend your using an electrician to inspect along with your choice of careers.
I teach electrical engineering...does that count? Al
Al Welcome to the forum and you ask a loaded question. It certainly counts in theory. ;-)
I like the boxes to be mounted above the insulation but that is just a work practice. Alternately I used to attach a string to the box and the other end at a rafter or other framing member. Anything to reduce the time rummaging in the insulation. I have also installed a raised walkway storage platform above the insulation in my attic which eventuall was replaced with a proper room.
Based on what you said, having an electrician 'check' was a good move. That said, I have an issue with the 'open' boxes, and how they were not corrected by either the original installer, noted by the 'inspector' or required to be covered by the 'electrician'.
Again, I would make a phone call to the Chicago area AHJs office and ask if there are any local codes regarding the insulation cover over the boxes. The NEC is moot on this subject.
It does not seem to be a trade practice but I made a point of installing all the J boxes up on truss chords or extra framing added for the purpose in my house so they wouldn't get buried in the insulation. It does use some extra wire tho.