Replace bathroom light with no junction box

[MikeA]

I removed my old bathroom light and there was no box. The wires were just fed through a hole in the wall. I have a new light fixture that requires being mounted to a box and weighs about 10 pounds. Can I just use one of those replacement boxes that has the tabs and is not mounted to a stud? Or do I need to mount a box to a stud (any hints on doing this and not tearing up my wall too much would be appreciated)? I guess another option is to use one of those fan boxes that usually go in the ceiling but use it between two studs instead? Thanks in advance Mike

[RBM]

You can't use a cut in box as it's only good for six pounds. What you can use will depend upon where the studs are, and if there is a vent pipe between them. A retrofit fan box may work, but you won't be able to fit it into a 2x4 wall without cutting it open. If there is a stud where you want to mount the fixture you can use a pancake box.

[David Nebenzahl]

On 10/25/2010 7:15 PM MikeA spake thus:

Walls plaster? drywall? Makes a difference; let us know.

For devices like switches and outlets, I like to use the "old work" type of metal box that has the two ears on the sides that are tightened by screws (but not the type that has the ears that get "squashed"). Now, these are rectangular and normally not suitable for light fixtures, which like to use round or octagonal boxes. But I wonder if the light couldn't be attached to one of these boxes with a crossbar.

Anyhow, 10 lbs. isn't all that much. In a plaster wall, I'd think that a tabbed box in a carefully cut hole ought to be sufficient.

[Molly Brown]

Just make sure all the conductors (wires) are tucked neatly in the =93replacement box that has the tabs and is not mounted to a stud=94 and make sure that the fixture is somehow securely screwed or bolted to a stud so it doesn=92t come off the wall and start the fireworks.

[gfretwell]

I bought a fan box the other day at HD or Lowes that would work in a

2x4 wall (although 2x6 walls are common in bathrooms, just for the plumbing). This thing had a square member on one end and a screw going through it for the other end. The box bolts on after you get it tight so you could get it in the wall. (tie a string on it so you don't drop it and lose it forever) A vent stack may still be a problem.

[Roy Quijano]

You can get a small pancake box that fits inside your fixture, install a cable clamp on it if you get the kind with knockout holes only, and attach it to the wall with wall anchors. It is really no big deal though, just make sure you make a good solid connection with the wires, seal it as best you can with electrical tape and you can just attach it to the wall with any means available. Roy Q T. E.E. Technician

[RBM]

How do you get the 12" bar into the 3 1/2" deep wall through a 4" round hole?

>

[RicodJour]

Depends where the hole is, no? If it's in the center, then it's probably a problem. Some of the extension bars can be disassembled, fed through the hole and reassembled. Pain in the ass, but it's doable.

But I wouldn't go that route. Cut a strip of 1/2" plywood blocking slightly narrower than the hole, put construction adhesive on the ends where the blocking will touch the inside of the drywall/plaster, feed the strip through the hole, and a few screws through the drywall/ plaster into the ends of the blocking on either side of the hole. If the fixture won't cover all of blocking and the screw heads, place another temporary piece of blocking on the outside and screw the two pieces of blocking together through the cutout hole to hold the inside piece in place until the construction adhesive sets up. The inside piece of blocking should have a hole drilled where the wire will poke through into the back of the pancake box.

R

[MikeA]

Thanks to everybody for the advice. I appreciate it. I'm heading to home depot today and I'll let you know what I end up doing. Thanks

[aemeijers]

Very carefully, which is why he mentioned the string. It isn't 12" long when you start- you extend it once it is in the wall. Skinny fingers and a 3rd hand help.

I'd be inclined to mount the light on a decorative piece of hardwood, finished to match the other trim in the bathroom, burying a pancake box in it if needed.

[RBM]

Unless it's something that I've not seen before, it is 12" long when you start. Typical retrofit fan box extends to 24", so it starts out at 12".