A while ago I had some electricians install a ceiling fan mount. Now that I've finally gotten around to installing a fan I've discovered that they didn't install any sort of electrical box to house the wiring. The hole they cut in the ceiling fell on a joist, so evidently they just gave up and installed a round resin adapter plate that they screwed to the joist, which the ceiling fan mount can then be screwed to.

Is this arrangement up to code (in MN) at all? How should I go about fixing it?

  • 4
    can you post a picture or a link for the adapter?
    – mikes
    Jan 5, 2013 at 22:46
  • What is a "round resin adapter plate"?
    – Jay Bazuzi
    Jan 6, 2013 at 0:56

3 Answers 3


Based on your description, I "see" the ceiling cut out, a resin disc screwed to the joist. The disc has two or more empty holes that correspond to the device mounting holes in a standard octagonal junction box. Then there's a length of romex cable just hanging loose to which you're supposed to connect the fan.

If your fan's installation instructions indicate some part of the fan can be used to make connections, such as the ceiling canopy, you may be in luck. Make the connections there. More than likely, they'll assume you are providing a junction box in the ceiling. First ensure the fan's mounting kit is compatible with your resin plate. You'll need to get the wires from the down pipe, through the plate and into a nearby junction box you will install. The fan wires need to be long enough that there's at least 6 extra inches after running into the box. They must not bind against anything.

You'll need an old work box, a blank cover plate, some wire nuts (may be part of the fan kit), a short length of 1/2" flex conduit, a flex to box connector, and a plastic conduit bushing to protect the wire insulation where it goes into the conduit above the fan. You'll also need a romex to box connector if the box does not have them built in. Any wire running in a concealed structural space needs to be in conduit or non-metallic cable (romex), or a few other less common options.

You install an old work box by cutting the proper sized and shaped hole in the ceiling in a place where the box will not hit anything above the ceiling but is close to the resin plate on which the fan will be mounted. Do not install the box at this time, I'm explaining what will happen, but there's other things to do first. You would place the box in the hole, the box's flange keeps it from being pushed through. A couple retaining tabs are turned with a screwdriver so that the box will no longer be able to be pulled out.

If the romex cable is not attached nearby to a joist, you'll need to do so through the box hole. Locate the hole so it's close enough to do this, but not so close the wire is kinked or crimped after the box is installed. Remove an appropriate knock out in the box to connect the conduit. You can cut or drill a hole if need be. After securing the romex, feed it into the box. Feed the attached conduit through the hole and back out through the resin plate. It can be routed next to the plate as long as the fan ceiling canopy fitting will cover it. Or cut a hole in the plate if need be. Install the box and cut the conduit to length at the resin plate. Install the protective bushing. Install the fan on the resin plate. Push the fan wires through the conduit at the resin plate and into the box and make the connections. Install the fan ceiling canopy and box cover plate.

  • I wouldn't use an old work box for a ceiling fan, the tabs on the drywall won't handle that kind of load.
    – BMitch
    Jan 7, 2013 at 20:32
  • Sure wouldn't. I'm suggesting the fan is supported by the resin disc. The old work box is simply a compliant way to make the connection, it is not supporting the fan, it's nearby adjacent to the fan. I'll try to edit my answer so this is clear. Thx for noticing.
    – bcworkz
    Jan 8, 2013 at 0:19
  • That's what I get for reading too quickly. Thanks for clarifying. +1
    – BMitch
    Jan 8, 2013 at 0:32

If you hit a joist, you can use a 1/2" round junction box designed specifically for this issue (drywall is usually 1/2" thick). Make sure to find one that's designed to support the weight of the fan. E.g. this one will handle ceiling fans of up to 70lbs.

junction box image

When you install this, you screw directly through the back of the junction box into the joist, so there's no need for the old work box with tabs or to open the wall up for a new work box that attaches to the side of the joist.


You should have at least three choices:

  1. A fan-rated pancake box. This is a low profile box that is about as deep as your drywall is thick. If the joist passes through the center of the hole, you can simply screw the box to the joist and hang the fan from the box. The pancake box is small, so you might not be able to make the connection inside the box. In that case, the top of the fan (shroud?) must be rated to allow a wire connection.

  2. A plastic (maybe metal is available as well) fan box that straddles the joist. This is another low profile box that has additional "fins" sticking out of the bottom of the box that allow for secure mounting to a joist or blocking.

  3. Fan-rated box with integrated brace. The brace fits between joists (above the hole in the drywall if the hole is unobstructed by a joist or blocking. You can twist the brace to ensure that it fits snugly between the joists.

When hanging a fan it is critical to fan-rated boxes for two reasons.

  1. The box must be able to hold the weight of the fan.

  2. The box (and its mounting method) must be able to resist the torque of the starting and running of the fan.

See this article for some examples of these fan mounting methods:


  • Answers the rely entirely on links, are not useful if the link dies, please try to include more information in your answer.
    – Tester101
    Jan 7, 2013 at 20:24

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