Installing Metal Ceiling - How to deal with exisiting electrical?

[TrickVert]

Well, after lurking and searching (a lot!), I'm getting started on finishing my 2-car detached garage. I'm planning on using corrugated galvanized metal (1-1/4" x 1-1/4" ribbing) for the ceiling, and about 3.5' up the walls, and finishing the upper portion of the walls with OSB (painted or cleared -- I'm not sure yet which).

I'll be adding plug-in fluorescent shop lights and will power those via surface-mounted outlets in handy-boxes using 2" ******* to protect the Romex from sharp edges. Easy. What's got me scratching my head, though, is some existing incandescent fixtures (currently ceramic bare-bulb units) that I want to keep for in-and-out trips, and already-mounted outlet boxes (four of them). The boxes (for lights and outlets) are a mix of blue and black plastic ones, all mounted with the expectation of drywall being used as a ceiling material.

One thing I thought of was to keep (and extend?) the existing boxes, and perhaps use some of the OSB to make a flush-mount "plate" of sorts.

Alternately, I might just cut down the existing boxes so they are flush with the ceiling joists, then add handy boxes right below. My concern here is there may not be sufficient extra wire to reach a new box. There should be, but I've seen some with only a couple inches of slack. I also want to keep the incandescent bulbs as high as possible.

Another idea is to cut a square hole in the metal, and build a frame (prior to installing the metal) and attach some OSB, effectively recessing the boxes. I saw in another post where someone recommended THIS to fill the gaps. This would be OK for all but one which is a switch for the "attic" lights. I'd be worried about sharp edges when using it.

Any ideas, examples, pictures will be appreciated.

Thank you!

 

[rburke65]

No help for ya here. It's rough with the corrugated metal. Is it already bought? I have used the white metal ceiling liner.....with the flat areas making it easier to mount boxes and lights. Good luck.

 

[The Cobbler]

....... My concern here is there may not be sufficient extra wire to reach a new box. There should be, but I've seen some with only a couple inches of slack. .......

Thank you!

you can add pigtales and extend the wire inside the boxes it it's too short

 

[TrickVert]

you can add pigtales and extend the wire inside the boxes it it's too short

Well, now, that just makes too much sense!

So simple I didn't think about that! (Wow.)

That would be fine for the outlets and my attic light switch, but unless someone has a better suggestion, the more I think about it, I'm liking the idea of an inset OSB "plate" for the incandescent fixtures to keep them as high as possible.

Anybody else?

Andy

 

[TrickVert]

No help for ya here. It's rough with the corrugated metal. Is it already bought? I have used the white metal ceiling liner.....with the flat areas making it easier to mount boxes and lights. Good luck.

I haven't purchased it yet, and if I can get a good deal on the flat material , I'll consider it. There's a place up near Denver, though, that sells factory seconds of the corrugated, and I can't beat the price. I also like the idea/look of the galvanized material.

Andy

 

[foamer01]

I have used the white metal ceiling liner.....with the flat areas making it easier to mount boxes and lights. Good luck.

I used the same material with absolutely no regrets. It comes in galvanized as well. I used 20 ft panels, they come up to 40 ft. Flats spots were great for electrical boxes.

http://www.menards.com/main/buildin.../steel-panels/dura-panel/p-2044929-c-5717.htm

 

[88e30]

I just installed 1" corrugated galvanized metal on my ceiling. My plastic electrical boxes were also set up for drywall. I unscrewed them broke off the standard depth tab and dropped them so that the face of the box was an inch lower than the rafter and would be flush with the finished metal ceiling surface.
I cut square holes in the metal with a grinder equipped with a cutoff wheel approx 1" bigger than the electrical box. I then made up some 6" plates with a 4" round hole in the center to use as trim plates to tidy up the light fixture holes.
Mine is new construction and bulb/fixture height was considered from the get go and lights were placed for maximum light and clearance.

If you currently don't have a ceiling installed and you are concerned about bulb clearance, why not install recessed lighting?

 

[TrickVert]

I'm not sure if I can lower the boxes easily or not, as they're the nail-in type, but that might be worth a look. The idea of a "finish plate" rather than a recessed mount is interesting, and might be simpler *and* look better.

This is more of a functional makeover than an aesthetic one, so I don't know that I want to go the recessed-can route. Not a bad thought, though.

Andy

 

[AnEv942]

Vent flue, chimney fittings? There are a bazillion different tin, galvanized fittings ceiling/ roof plates, caps etc that could be utilized. My first thought for an untrimmed hole was flue pipe, cutting circle in corrugated.
Cut off some flue pipe. Insert or drop thru say 8" flue pipe with crimped end exposed inside. Tab so doesn't fall thru. Cut hole to match,set against box in a larger piece of sheet, mount to box with your porcelain or other fixture. Would only protrude-length of crimp, extend inside to **** again box sheet. Still have access to box/wiring if needed. maintain the metal look. Pretty sure existing boxes would need to be moved up flush to ceiling joists. Just stirred my imagination Sounds like fun anyway cause now Im looking at my exposed ceiling...

 

[TrickVert]

Following up on this: The project is well underway, and I expect the ceiling to be finished this weekend. (I don't have much spare time, can you tell?) For the one area where I had two boxes in place, I ended up making a filler plate, then trimming around that with J-channel into which the corrugated metal will go. Since I already had to go around the attic ladder, this was a simple choice.

I'm just going to replace other single boxes the metal "handy-boxes." The material I chose for the ceiling ends up being only 1/2" thick, so no worries on needing to extend the current lengths. Oh, I also just used 4" octagonal boxes behind new incandescent fixtures, figuring the loss was acceptable.

Andy

 

[TrickVert]

Well, it's not perfect, but the ceiling is finished.

On to the walls!

Andy

 

[captain14]

Very nice finished project. How much light is reflected off the panels back onto the work area?

 

[TrickVert]

Very nice finished project. How much light is reflected off the panels back onto the work area?

Thanks. I'm pretty happy with the results. I should have put in landing areas for the ends, though, as there's a good amount of undulation that I was expecting gravity to take care of (and was relying on to have the metal rest on future trim boards).

The metal has to be improving the lighting a bit, but it's hard to say how much since:

1) I didn't measure before and after luminance levels.
2) I moved the fixtures a bit from their original locations.
3) I changed from ceramic bare-bulb fixtures to these.

I will say I'm rather impressed with the light level from just these four 75W bulbs, but can't wait until I have twelve 2-bulb fluorescents hanging in there!

Andy

 

[blackdart66]

Your solution looks good !

I have done 2 metal ceilings and have found the easiest to be to remove the existing box and replace with a handy box screwed to the rafter. I use the handy box as a junction box and just pigtail on with a couple of feet of romex out of the handy box that I just let hang till I install the ceiling. The reason for this is that I hate trying to measure for a box and then fit it on a ceiling with a difficult to cut material. It is also just about impossible on ceiling liner to hit the flat spots of the metal. Murphy's law says you won't. You obviously didn't have that issue with the corrugated. When I am hanging the metal, I just find the best place for my box within range of my wire that is hanging and cut a hole for a remodeler box. All I have to do is kind of fish the romex through the hole and screw the sheet up. Then I install the remodeler box hang the fixture and all is good. This is not a good idea for a heavy fixture but works fine for most incandescents.