Why do I have saw out the bar the electric box hangs on to replace it with a fan rated bar and box?

Question

I had a ceiling light and it had a metal bar and a electrical box. The home is not that old but The electrical box was not ceiling fan compatible so I removed the box. Now the bar is solid I could hang off the thing and it would not move and believe me holding me is more weight than the ceiling fan. To install the ceiling fan with the bar and electric box that is ceiling fan approved I have to saw out the existing bar and put a new one in. My question is why do I have to do that?? Isn't there some electrical box that I can buy that will work for the ceiling fan and the existing ceiling light bar??? If there isn't there should be But please tell me there is cause I don't want to saw the existing metal bar in pieces.

Thanks

Answer 1

It would be preferable to know what that bar is secured to and how well. Fans vibrate, and that can introduce a failure mechanism lights (or you), as a static weight, don't have. It sounds like I'd probably use the existing bar if it was my own house, but that's comment, not recommendation.

Answer 2

It depends on if the box was installed as an "old work" box (i.e. after the drywall went up) or as a "new work" box (original to the house, or during a remodel when drywall was removed).

In the old work case, the box is designed so the bar simply presses against the joists on either side. You should be able to twist the bar 90 degrees so it's parallel to the joists, then fish it out through the hole for the existing junction box.

However, if it's a "new work" box, the bar may be nailed or screwed to the joists, in which case you'll have to figure out how to get at it from above or remove a chunk of drywall to access it fully.