Electrical – How to install can-less down lights in new construction

The symptom of the gap you have in all my experience with recess lights have been the rough in housing has room for deflection. As you push the trim in place, the rough in pushes up also under the tension of the lens going in and it stays pushed up until the lens bottoms out on the ceiling and is released. The housing relaxes back down and creates the gap.

I have had some success minimizing the gap by twisting the trim slightly after the trim is meeting the ceiling. Twist it in the direction that keeps the tension fingers out on the lens. The wrong direction may allow the tension fingers to collapse for removal and you are back to square one.

If that does not work to your satisfaction, I have glued the rough in down to the drywall so it is stable enough to not rise when inserting the trim.

Blue tape the finished drywall to keep it clear of the adhesive you choose to use, it can be practically anything. Construction adhesive or painters caulk would be my choice. Push up on the rough in to expose the gap if possible of the upper drywall surface and rough in lip. Inject a lot of the tube in the space, it will be messy, have paper on the floor. Let the rough in back down, more may ooze out, keep it clean remove tape and let dry for a while. A day or two will work, longer the better, then try to reinstall.

Accessible is a somewhat relative concept. You need to fully remove a recessed fixture from a ceiling to access the connections. This is a bit more difficult than pulling a switch to get at the wires, or even dropping a canopy style fixture, but it does meet the criteria of accessible.

But one of the main rationales for the rule seems to be to ensure a troubleshooter knows where all the connection are, that none are truly buried in the walls where they can't be found.

I don't know if the code has considered your solution, but it sounds like the box you are suggesting is buried, even though it is attached to the recessed fixture. In a sense, you are modifying the fixture in a way not contemplated by the manufacturer. But it might pass muster with some inspectors since it sounds like the junction would be accessible if you removed the can.

There is another way that might suit. The code now allows for certain in-wall splices that can be buried, such as these.

The old wire is inserted into one section of the device, clamped, and screwed in. A new wire is inserted into the other. The halves then snap together and the resultant splice can be buried in a ceiling or wall. If feasible, the completed clamp should be attached to a framing member, but I don't think the code requires it if the wire is left in an unaccessible area.

You could attach this splice to your old wire and run a short extension to your can.

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