This past weekend I installed a ceiling fan to replace an already existing light fixture. I had to replace the plastic electrical box from when the home was built in 1992.
I am unable to get into the attic for this specific fixture as it's in a spot that I am physically unable to reach due to the layout of my attic and the support beams so I used a retrofit Saf-T Brace rated for ceiling fans.(see below) I'm guessing this box was installed before the drywall was put up because of the location it's at, there really is no way for a person to fit into this small corner of the attic.
When I went to install the brace bar, I realized there is a vapor barrier bubble around the already existing ceiling box with blown in insulation on top of it. It's a 6 mil poly sheet which I am assuming is just stapled and caulked on. I went ahead and cut a small hole on the side to make the brace bar fit through it, secured the bar, installed the box and installed the fan.
I now realize I should have fixed the vapor barrier but since I cannot access it from above - what is the best course of action? I don't really want to have to cut a bigger hole and repatch drywall if I don't have to. Could I use some fire retardant spray foam to seal it up by taking the fan down, removing the box and blowing some in there? Is it even a cause for concern? 
