Hi,
I'm trying to install a ceiling fan in our guest bedroom. 1915 house, two condo conversion. Other fan I already installed had nice modern box and romex in the ceiling. This room had no box under the light, and had many wires coming out of the ceiling : 2 pair of what I think are K&T, sticking out of a giant ceramic fixture, plus a romex cable coming in from the side.
Ceiling is real plaster (lathe wood and goop). There is about a 4" hole in the ceiling, maybe 1-1.5" deep that all the wires were crammed into.
One pair of K&T is tied together and off, and one pair is tied together and splices into the white line from the romex. Hot to the light came from the romex.
So... I'd like to put a junction box for a new fan (note the fan instructions say to mount directly to wood joist or cross-member, not the box itself).
My plan is to check the attic, pull the cermic fixture, insulate K&T with heat shrink tubing, and mount a box.
Any tips or suggestions? Any good tips to cut into plaster without the whole ceiling coming down?
I've attached the best picture I could take of the mess as it exists today.
Thanks in advance,
Matt

If you know how (there is a SPECIFIC way) to do it, you can cut the K&T wiring back, (the NEC code book will be helpful) splice it to romex and run that to a junction box that is mounted correctly and rated for fan use. If you need a wood member to hang the fan from, just put a 2x4 hung on joist hangers across between two ceiling joists at the correct location and hang your junction box there. This assumes that you can get above the ceiling and work there. If the plaster is rotten, you will be replacing a section of it. The only hint to cutting it is a sharp saw, be careful, and hope you are lucky.

EPM

Good picture. Why does it look like it got hot in the junction wire area? In rehabs like this we use a "pancake" electrical box that is very shallow and can be screwed onto the lath providing the lath is sound and shim so its flush to the ceiling or if it sticks out a little and the new fixture can cover that protrusion that fine. Now hear is your real problem. This shallow "pancake box application will not work for a ceiling fan The fan will probably be way to heavy for the box screwed into lath and among other reasons.. Look up in the ceiling and see if you can see a floor joist This is whats needed to carry a ceiling fan properly. Your directions are correct except the word "joist" can be a 2by4 s or a 2by6 that one can be laid flat between the "ceiling" joist above the finish ceiling or two with joist hangers. I do laugh at those directions, who built the house joist to be exactly in the right spot to hang a ceiling fan. If we followed those "exact" instructions the ceiling fan company would be out of business because of to be directly to the 'Joist" ceiling fans can be very heavy and will move and vibrate and can jump out of the ceiling and fall short and possibly cause a fire. Get in the attic or crawl space above that location? Install some bays between the "bays" and flush the 2bys to the ceiling where the lath is and get your metal junction box first to caulate the placement depth of the 2bys so when you screw this box in from down below the box is flush to your finish ceiling.One flat 2by would be good. Without a doubt you have to have good sound solid anchoring for the new box. They make round plastic boxes that you push up into the hole and when you spin the screws there is tabs that spin out and pinch the box flared sides to the ceiling. Again this is for a "light" light fixture in ceilings There are many ways to "rig" up this and some are really Chancey at best. Solid and sound is the key thought. I don't know how heavy you want to get into this, Another way if you can't get physically get above the ceiling is from below find out where the ceiling joist are from side to side and sawzall that out for a 2by and nail that into both sides of the joist bay that the your hole is in. A sawzall might vibrate the ceiling too much and that also depends which way you lath is running. Right now "Harbor Freight" has on sale a great cheap tool "Multifunction power tool Lot no 65700" on sale for $39.99. Dremmel is also making them now in big box stores. This tool can cut your plaster/ wood perfectly without shaking the plaster and lath apart and greatly cut the dust factor down. Always plastic in work area from ceiling to floor. Cutting old plaster is 10 times worse than drywall. In my city 1754 all of the houses are plaster lath and plaster brick. Sorry for being wordy there are a lot of possibles here and I wanted to cover as much as possible. I know I hate it when " Man I wasn't told that in my instructions" No But what if" Hopefully these are some answers your looking for let me know if this helped.
Happy Holidays!

You could also bolt the fan directly to the joist and perform all the wiring within the metal fan canopy. This SHOULD be legal because that's how a swag kit works, but I can't guarantee that, I am not a code expert.

Thanks all for the feedback. The only thing keeping me from trying to fit a fan box is that I don't know if I can remove that insulator that the two older wires thread through. Wood behind looks and feels solid to the push like a cross member or joist. I'll check it in the attic also.

Hi,
Thanks again for feedback. Attached are pictures showing my progress. Removed the old iron mount through which the wires threaded, put on heat-shrink on individual wires and bundles where I could. After I get in the attic and reinforce with proper would bracing, I think I have two options. Advice appreciated!

Option 1 : get a fan-rated box, cut four holes in it for the wire bundles ( I can use the iron fitting that I took down as a template - picture also attached), and run the additional romex line through the side knockout. It'll be crowded, but I think it'll work.

Option 2 : mount a junction box in the attic on a nearby joist (I saw some with up to 6 knockouts at home depot), then run a romex line from there down through the hole in the ceiling. This particular ceiling fan actually specs to mount directly to wood, so in *theory* I wouldn't need a ceiling fan box for this option.

I'm leaning towards option 1, I guess mainly so that in the future new fixtures can go in easily.

Thoughts appreciated
Thanks much
Matt

What is the wood that the wires are coming through? Just a piece of plywood?

I don't think it's plywood - it almost looks and feels like redwood. But I doubt it, since it's in MA. About 6" wide, 1/2" thick.
I'll know more when I pull it out in the attic today.
Is it OK to drill my own 4 "knockouts" in the bottom of a junction box?

I would prefer option #2. Since there is attic access, the best option will be to pull back all four old cables and cut off more metal sheathing to expose new insulation on the wires to eliminate any heat shrink.

All existing cables would now be in much better condition with no chance of shorting out due to bad wire insulation. Extend new cable from the attic junction box to the new fan rated outlet box.

The wood is chestnut, very popular in construction in New England years ago, before there was a blight that nearly destroyed the chestnut tree population.

Hi,
OK I think I also like the option of a junction box in the ceiling. Trick is, there is very little wire available to pull back and cut so the box will have to be down on a joist, or more likely, on the very piece of wood I'm fitting in for support, a few inches away from the opening.

Do I need to worry about an enclosed metal junction box that might be completely covered by insulation? (pink and blown-in). Do I need a specially rated box for that? Someone told me I did, but I tend to doubt it.

Other question - I got a length of metal-wound-shielded 14G 3 conductor to go from the box in the attic to the opening in the ceiling. Can I just use romex? I'm guessing the metal-wound is in theory safer, since it's all enclosed.

Thanks again!
Matt

Matt,

There is no knob and tube wiring in any of the pictures. There is romex and AC cable (bx)

If in fact the bx does not go to a K&T connection it will need the proper connectors to keep

The continuity of the metal sheath. NO, a box can not be buried in a ceiling cavity, how

Would you ever get to it later on. Matt, I'm sure you can get the fan to work, but, with the

Condition of the wire that I can see I will certianly recommend that you hire an Electrician

To finish the job for you. There are just too many things that you don't know. I'm not

Trying to be harsh to you, rather I'm looking out for your best interest.

By the looks of you picture you have 10 or so current carrying conductors there. To junction that all in one box will require a box with more than 20 cu. in. volume. There aren't any fan boxes that are that big. A 4x4x2-1/8 box will be about the smallest allowed to junction all that. See the electrical code table 314.16 about box fill. See this posting at the top of the electrical page to read the code. https://www.askmehelpdesk.com/electr...ne-270277.html

Also you don't want to bury any junction boxes. You may have to pull several cables back to more than one location to get enough cable length to get above the insulation. I attach lengths of 2x4 vertically on a joist and long enough to get my junction box several inches above the insulation to mount my boxes. Then run cables between those j-boxes to connect everything back to what it was before and then run just one romex down to your fan box.

EPM

All,
Thanks again for the replies. Very informative. After cleaning up things in the attic and installing a junction box down at the joist spanner (2X6 I bolted between the joists to support the damn fan) and re-wiring the way I found it, the voltages are all wrong. benaround, thanks also for your message. Very kindly worded and I agree. I don't mind minor straightforward projects involving modern wiring that WORKS, but 5 sets of 40-60 year old BX spliced into modern is way over my head. We've got a real electrician coming in next week to finish the thing off. I've always had a hard time hiring others to do what I think I could do ( I actually am fairly handy, and have degrees in engineering, and have worked with high-voltage equipment in the past... but it was all newly built and well documented. Funny that), but sometimes you got to suck it up for your best interests.
I pulled the wires into the attic and put in a box for now, just to clean things up and allowed me to install the fan support wood, as well as fan rated ceiling box. I'll leave it to an expert to finish it off (and maybe peak over his shoulder to learn as much as I can)
thanks again!

removation,

Very wise. If you watch and pay attention, you can chalk some of the cost to education. I have done a LOT of that in the past and it has been VERY helpful.

EPM

I wanted to replace the k&t box like this set up. There is no romex. I have lath and plaster with maybe 1/4 inch to the fixture. Will a shallow box still work? Would it be better to roto zip a larger whole and put in an old works box and start fresh?