Installing junction box for exterior light

[Kmarissa]

Hi all,

It seems even my simplest projects become complicated. I'm sure you don't remember, but I had previously posted about a broken porch light that we have, a lantern-style pendant hanging from the porch ceiling. We bought a new light, and loosened the old light fixture's canopy enough to see that, as we feared, there's no junction box. The wiring comes out of a very small hole in the ceiling, probably the size of a silver dollar or so, and the mounting bracket seems to just be screwed directly into the existing (probably original?) beadboard. To the best we can tell with our stud finder, the light fixture is right between two joists, and is centered to the front door (so moving it over against a joist would look off-center and weird).

If this were a plaster ceiling, I'd be happy enough to take out a bit more plaster and install one of those junction boxes on the adjustable bars, between the joists. But, I'm not sure how to deal with the beadboard, which I really really want to keep (besides which, replacing the entire porch ceiling isn't in the budget anyway). What are my options here? What are the chances that individual boards can be removed to allow for installation of the junction box, and then replaced after wiring is complete? Do I need to start looking for salvaged beadboard that matches ours, to patch the hole? Despite the existing mounting bracket seeming very stable screwed into the beadboard, I'm worried we'd be causing a safety hazard if we attach the new fixture the way the old one was attached (plus of course, we wouldn't be bringing it up to code).

I can include some pictures later, if that would help.

[vvzz]

Use pancake box. Its surface mounted and is considered a proper junction box

[GibsonGM]

Yup. Don't forget the ground wire (if there is one, LOL).

[Mick_VT]

pancake box, or use an old work box with lugs, unless you plan on adding a really heavy fitting the beadboard should support without needing a bar

[Kmarissa]

Thanks everyone! So pleased that there seems to be a relatively simple fix! Usually any project I undertake is the other way around--it seems simple to fix, but quickly becomes complicated.

[mjt]

As others have mentioned, a pancake box can be surface mounted and the eared "old work" boxes are fine for lightwieght fixtures. I've used both previously depending on the situation and these (photo below) in the past as well for heavy fixtures. The bar detaches from the box so that it will fit into the hole in the ceiling. The one end of the bar is threaded so that it can be expanded to fit snugly between the joists simply by turning the bar with your hand once its in the ceiling. The box can be fastened anywhere along the bar. They are sturdy enough for use with ceiling fans if you make sure to get the protrusions to bite into the joists. They can be found at any big-box store in the US.

[Kmarissa]

Mjt, I had seen pictures of those but always assumed they screwed in at the ends. If they have teeth instead, that could be a great option.

[Mick_VT]

Do bear in mind that if your new fixture is not heavier than the old, you really don't need to do very much. Those bars are for hanging substantial weight. Your beadboard will carry quite a lot of weight without the need for any extra support

[mjt]

Mjt, I had seen pictures of those but always assumed they screwed in at the ends. If they have teeth instead, that could be a great option.

The "new work" ones nail or screw in at both ends and require a new construction environment with an open joist bay. As you might expect, at a big box store they'll have huge quantities of those on the shelf, but only a few of the "old work" ones...

The teeth are visible on the right-hand side of the photo, as is the threaded rod that make it expandable. The photo makes it hard to see the teeth on the left-hand side. The black plastic parts, just interior of the teeth, provide the correct spacing from the back of the ceiling so the junction box doesn't stand proud of the surface. They also ensure the threaded rod actuates, rather than spinning uselessly, when you turn the square body.