One of the fun things about remodeling an old house is seeing all the ways previous owners have gone about solving problems. During my workings I’ve come across some hardware that I’d never seen or heard of before.
I just finished rewiring (almost) all the second floor outlets and (almost) all the first floor overhead lights. This wasn’t really in the plan. While working on the second floor bathroom remodel, I discovered that the crawl space between the bath and the roof line was filled with old (probably 50’s) rock wool insulation with knob-and-tube wiring running through it. These days, code does not allow you to insulate (with any kinds of insulation) over knob-and-tube. It’s a fire hazard. So I decided that we needed to fix this. That meant removing the old insulation. (Incidentally, Fine Homebuilding suggests that it’s fine to leave it there and just add more insulation over it. Oh well.) Then I needed to replace all the knob and tube that was in the crawl space. Turns out it’s all the original wiring for the house overhead fixtures and second floor outlets.
So, I went around the house and over the past several months replaced a fixture or run at a time. This turned out to be extra difficult when the original bungalow was built with joists going inline with the peak of the current roof. So a later addition added cross beams and proper joists in the new area. Oh and all my first floor ceilings are 10-12 inches below the original ceiling but still plastered. Of course I didn’t want to make holes in the ceiling or walls if I didn’t have to.
To support the fixtures that were suspended in these sub-ceilings, they installed brackets that can be nailed or screwed into the joists. Fortunately the sub-ceiling also has joists running through it. There are two types of brackets I found. The one at right was more common. As you can see the bracket is a metal rod on which a triangular nut can slide. The movable nut allows the ceiling box to be attached at any point between the studs.
You put the ceiling box over the nut (through the center knockout in the box) and attach a sleeve that has a whole in the back to line up with the nut. Then screen in the set screw which acts to hold the ceiling box on the bracket and sets against the rod so that the nut doesn’t slide any more.
Of course once I had seen this a few times I discovered it at my neighborhood True Value. They still make similar brackets. I’m sure, if I ever install overhead fixtures elsewhere, that I’m likely to end up using one some day.