How do I remove an electrical box in my ceiling?

Question

Trying to install a ceiling fan but first I need to put in a new outlet box with a fan brace. I removed the existing light but I can't get the old electrical box out. I've unscrewed everything that was in there but I don't know how to get the box out.

Anyone have any advice?

Answer 1

It sounds like you're dealing with a metal ceiling box & an NM Cable wiring system.

The typical metal box in a ceiling is either an 8-B (Octagon) or a 1900 (4"x4"). The 8-B does not usually have a mud ring installed. When used in a ceiling, the 1900 will generally have a "square-to-round" device ring installed. Both are typically mounted using a metal strap spot welded to the side of the box. These welds don't break very easily.

[Sometimes, these boxes are mounted with a cross-strap, similar to the way a fan box is installed. If that is the case, you may be able to use the strap, and just change the box; that depends on how it was mounted to the strap.]

You will probably have to cut out the ceiling to remove the fasteners securing the box to the joist above it. Be careful not to cut the old cables when cutting through the drywall; it is best to do this cutting by hand using a drywallers "jab-saw". Most of the straps on 1900 boxes extend past the box by about 1-1/2", so start a cut heading toward the joist about that far from the edge of the box. When you get to the joist, you should hear and feel metal, not wood. If you feel wood, then you are probably far enough from the box to use the same measurement to cut to the joist on the opposite side of the box; now you can cut away from the joist until you are even, or slightly past the end of the box. Push the jab-saw through the drywall about 1-1/2" past the joist it is nailed to, and cut along the joist until the cut matches up with the cuts you made on the opposite side. Cut through the 2 small areas between the cuts (where the joist is) with a utility knife and you should be able to use this piece as a patch.

You should now be able to see if the box was attached with nails or screws. Use the appropriate tool to remove the fasteners and install your new fan box. Re-install the cables using listed box connectors (be sure you attach the equipment grounding conductors to the metallic box using a grounding s***w, to each other, and to the equipment grounding conductor on the ceiling fan).

The easiest way to disguise the patch is by using a ceiling medallion between the drywall and the fan trim. If you don’t want to do that, you may want to use a larger patch; this makes it a little less visible when light reflects off of the patch.

With any type of cable assembly as a wiring system, you can also move the box location slightly, just remember that Code requires a minimum of 6" of free conductor (outside of the box), and that Type NM cable sheath must project at least 1/4" into the box, through the connector or clamp.

If you have a raceway installation (with any type of conduit), you will have to replace the box exactly where it was, or the pipe will not line up with the knock out openings in the new box.

Answer 2

you need to cut the ceiling out around the box

Answer 3

The boxes are just screwed or nailed in place.  Use a little more  persuasion.

Answer 4

The box is attached to ceiling rafter, typical method is a couple of nails through a bracket on the outside of the box. Your best way is to use a saber saw with a metal cutting blade and cut the bracket away from the box.  This is hard steel and it is not easy to cut. The alternative is to open the area around the box enough that you can remove the box with a pry bar.  How heavy is the fan that you are installing?  Certain lighter weight fans were exempt from the support box requirement. Check the code for the weight specifications.

Answer 5

cut it out with a chainsaw

then shove the new thing in its place