Is this anywway legal to do? I was told it would be OK to do this just drill out the back of the box and thread the nipple into the gas pipe with a washer to hold the 4in round up. This is in an old house with large plaster medalion's
I recommended using gum to stick the box up to the joist and got a funny look.

I usually remove the gas pipe. Either way it is a pain. I had a live one once and that was a little scary. If your going to use gum make sure it's not sugarless. This has far less holding power than standard gum.

OK, Yeah, I know, I'm 1,000 years old.

When I first came in the trade, there was still provision in the DC code to USE the gas pipe, not only for support, but it told us what we had to do to pull wires in it, and how many RW's and TW's we could put in a 3/8" pipe.

I expect it's frowned on now

BTW, that was back in the ANCIENT early 70's.

Gas pipe? Are you referring to the old iron pipe they used to use as a raceway? IS the "gas pipe" being used as a hickey for support of a rather large fixture?

-Randy

The box would be supported by the pipe only. Then the fixture would be supported off the box.

I have no doubt about the gas pipe being able to handle a pretty sizable load, I'd probably use a good size washer & the use double locknuts to make sure they don't come loose... is the box rated for the weight of the fixture?
If all these things come together, I don't see any problems.. Although if the pipe is your raceway, there might be a code issue Im just not thinging of right now...

-Randy

I ran a 4.25 in hole saw up into the nipple of the gas pipe for a center location and cut the plaster and pipe in no time. Then installed a box and brace.
As far as the pipe being able to support the weight, not in this house. On 2 other locations like this in the same house I made a small hole on each side of the medalian and cut the pipe and it slid out of the way no problem. It had no clips as the hole pipe run was loose and able to move so all the weight would have been supported by plaster and wood lathe

In Chicago I used to run into a lot of round ceiling boxes with the gas pipe attached to the center KO. Usually the box was also attached to anywhere from 1 to 4 1/2" black rigid pipes. That box wasn't going anywhere!

Seen that in the Northern Chicago suburbs too. Just make sure the gas is disconnected from the pipe before hooking up!

(Yes, a friend of a friend story - supposedly happened to my foreman in an older home once!)

JoeyD,
Without a more specific description of the age and construction of the house, what I'm going to say is only a generalization.

The original gas light fixture, that the gas pipe povided fuel for, simply hung on the end of that gas pipe. Hanging an electrical luminaire off that gas pipe, whether the gas is on or off, will not present any more stress on the pipe than the original gas light.

The presence of the medallion, to me, hints at historic significance that, if at all reasonable, should be preserved,. . .so hacking at the location to quickly get done may not be practical. Rather, the client can likely understand, and value, that marrying contemporary material to a historic system will take more time in order to minimize collateral damage.

Over my career, I've worked in a lot of old dwellings that were first lit with gas. As the building aged and the availability of electricity became reliable, the gas fixture was removed and replaced with an electrical unit. In some cases, the homeowner would seek out and install fixtures manufactured to provide both gas flame light and electric light. IMHO, the finished surface appearance of rooms that are from the gas to electric conversion period, if still present, are of significant historic importance and valuable in its own right.

"The presence of the medallion, to me, hints at historic significance that, if at all reasonable, should be preserved,. . .so hacking at the location to quickly get done may not be practical."

Al, To me hanging off the pipe would have been the quick and hack way to do it. I saved the medalian by cutting on each side of it. This is a rewire of an old house so patching was OK.

Cool!

Among other devices, when the gas pipe is removed, I've come to appreciate fan braces. The additional material cost is offset by the labor savings, IMO, and there is no question of the weight bearing ability afterwards.

I've also learned that most (4 out of 5) of the gas light stubs in my area come down from a Tee or a 90º fitting. My channel locks have been an adequate pipe wrench. I keep a small assortment of plugs and pipe dope on the truck.

The gas pipe that is site bent at installation is the worst to work around.

For me, the interesting situation arises around a turn-of-the-century fixture that is manufactured to mount to the gas pipe stub. When I rewire, I will need to install a outlet box, most commonly a metal 4" octagon, for the cable to end in and to splice to the luminaire conductors. I've never tried using nonmetallic boxes, and drilling them is arguably outside their listing.