I am installing two Hunter ceiling fans in a basement room in my house that I am fixing up. These are neat-looking tropical style fans -- not the largest variety, but still a little heavier than one might initially assume. The instructions explicitly say NOT to hang the fans from plastic outlet boxes. However, what we currently have installed in the ceiling (currently just used for lights) is in fact those familiar blue plastic outlet boxes. To take these out and replace them with metal outlet boxes would be a massive chore -- I'd have to take out a large section of drywall, and then repatch, re-mud, and repaint.
OR, I could defy the instructions and hang the fans from the plastic boxes.
The blue outlet boxes are VERY well attached to a joist -- very firm, very solid (in fact, they would be a major pain to remove). I assume the potential problem with the plastic boxes is not the possibility of the box detaching from the joist, but rather the possibility that the plastic screw holes in the box won't be adequate to hold a relatively heavy and vibrating object.
Ordinarily, I am a very good rule-follower, and rather safety conscious, but perhaps I'd be willing to make an exception in this case. I am thinking that even if worse comes to absolute worse, and the fan comes crashing down, then I am only out the cost of a fan.
Any thoughts on this matter are much appreciated. Has anyone ever similarly defied the rules and hung a ceiling fan of moderate weight from a plastic outlet box? Did mayhem ensue, or did everyone live happily ever after?
Thanks again for any info!