My question concerns sealing a box cover to the junction box.

I saw reference to this on a home improvement show. Also, some junction boxes are visible on the lower level near the parking garage of the building where I work, and I can see some type of sealer that oozed out between the box and the cover plate.

I referenced my 2005 NEC book, Art. 314, but found nothing specific. I'm asking as I recently rewired my house and due to some framing constraints I had to put some junction boxes in the upper crawl space. Per the NEC, would this qualify as a damp location? Need to be sealed? If yes, special pre-seal plates available, or use a good silicone? Thanks.

By upper crawl space do you mean something like an attic? This would not be considered a damp area. The junction box should be covered with a soild plate and be according to code.

Ballenger is correct, that your "upper crawl space" only needs a standard cover on any junction box.


Unless you would consider your crawl space as a damp location, which I doubt.

The reason you saw caulking oozing from a box in the parking garage is to seal the space above from fumes and retain fire proofing rating between a garage and occupied space.

Thanks guys. The upper crawl is the "attic" area. The sealer I see on the boxes now makes sense as all of the conduit going from the hallway through the garage wall is also fire stopped/sealed. I guess I should have figured that out since I fire stopped all conduit & piping running between floors in my house, but I guess that's how you learn. Thanks again.

Anytime friend