Convert RMC Flat Pan to Paddlefan Support

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al hildenbrand

al hildenbrand

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Minnesota
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Electrical Contractor, Electrical Consultant, Electrical Engineer
iwire said:
I would leave the boxes in place and support the fan independently of the box.

One possibility would be to remove the KO that is left and stick a 'Sammy' http://www.itwbuildex.com/sas_wood.shtml on the end of 1/4" threaded rod, run it up through the KO and into the wood above.

Once into the wood enough cut the threaded rod, install a fender washer followed by a nut to tighten up against the box to cover the KO hole and use the remaining threaded rod sticking down to support the fans bracket.
Click to expand...
If the wood above the flat pan is a 1?" wide framing member, this is a great solution.

I haven't explored the location, other than to take the snap in the OP, so I don't know, yet, what is above the flat pan, other than it is not lathe.

In my working area, for similar aged RMC / flat pan installations, the flat pan has been positioned by everything from a full sized framing member to 1 x 4 toenailed at an angle.
 
iwire

iwire

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Location
Massachusetts
al hildenbrand said:
If the wood above the flat pan is a 1?" wide framing member, this is a great solution.
Click to expand...

Framing member or the subfloor above, either way it would work fine.

A house of that age in my area would have at least 7/8" floor boards with 3/4" hardwood on top of that.

Get a sammy into the wood 3/4" to 1" and it would hold any fan you might hang ..... excluding Big Ass Fans.
 
renosteinke

renosteinke

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Location
NE Arkansas
Anchors? I don't know what a 'sammy' is.

Most fans -thanks to NAFTA - these days come with a steel cable in them, that you attach to a screw eye that is itself set into solid wood behind the box. The reasoning is that Canadian rules require this independent support.

Older electrical conduit was typically painted black, and might not have any galvanizing. The boxes were also black. "Shiny silver" wasn't common until the late 50's- when boxes had to be redesigned to make room for the ground wire.

What's the difference between a pancake box and a fan box? As best I can tell, the fan box has a pair of #10-32 holes in the back. You hang the fan from these, rather than the using the usual ears.

Cloth wire? Not bad, but often damaged by heat from over-sized bulbs. I usually re-insulate as much as I can with shrink tube, just on general principle.
 
Finite10

Finite10

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Location
Great NW
jaylectricity said:
Even better, the new paint will match the recent paint.
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314.27, C says the box needs to be listed and marked. That's because it's a dynamic/live load. The pan box version has special mounting holes/ears. 35 up to 70 lbs.
For 2011 if you run 3 wire to a box in a bedroom the box needs to be identified for paddle fan. Now builders can't sell a "paddle fan prewire" to a homeowner that will hang one on a 3090 nail-on.
The homeowner's failure to plan is the OP's problem... why? Cut the hole man. Sheet rockers have the technology to patch.
 
Nium

Nium

Senior Member
Location
Bethlehem, PA
Careful with the saw

Careful with the saw

Screw the fan brace to the wood the existing box is mounted to.

If you remove the box and are next to a joist
Arlington
http://www.arlcatalog.com/Fan_Specialty/Steel One Box(TM).htm
or
Westinghouse
http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

If you remove the box and are on a joist
Steel City56111 CFB (1/2" x 4" Pancake)
Arlington
http://www.arlcatalog.com/Fan_Specialty/Fan Fixture Mounting Boxes for drywall.htm
or
http://www.arlcatalog.com/Fan_Specialty/Fan Fixture Mounting Box lowest cost L-shaped.htm

If you remove the box and are in the middle of a joist bay then as previously suggested a fan box screw-brace combo.

Any box that you chose (by where you end up in the joist bay) should allow mounting with minimal damage to the fresh drywall and all except the plastic L boxes are compatible with conduit.
 
Nium

Nium

Senior Member
Location
Bethlehem, PA
Screw the fan brace to the wood the existing box is mounted to.
Click to expand...

I had meant to write BOX not brace and I could have sworn I did. Hmm computer gremlins.

With plaster n lathe and gas piping I've noticed that the pipe is usually located next to a joist and not in the middle of the joist bay. For what it's worth.
 
al hildenbrand

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Nium said:
Screw the fan brace to the wood the existing box is mounted to.
Click to expand...
Nium,

The problem is that the "gas pipe" is actually Rigid Metallic Conduit (RMC), originally manufactured around 1908, and painted black (it's not galvanized) and threaded.

The RMC contains the branch circuit conductors.

There are two locknuts on each threaded RMC end, one on each side of the flat pan.

From the back (top) of the flat pan, down to the finished surface of the new drywall ceiling, is 1?".

The boxes you suggest stand 7/8" proud of the finished surface, and only their top corner touches the framing.

How are you handling the cutting and/or re-threading of the RMC?

Also, @Finite10, with reference to 314.27(C), if I don't support the paddlefan from the box, the box doesn't have to be a paddlefan box, no?
 
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S

sameguy

Senior Member
Location
New York
Occupation
Master Elec./JW retired
I see one pipe the other item is a nipple for the Hicky to screw on to see the two mounting screws; the box could be held with a spanner bar that is nailed joist to joist. Good luck getting that out.
The screws that hold the fan frame are hardened aren't they?
I agree cut a hole so you can work and let them fix it, why people wait to call us is not our fault. If it was the plumber they would cut a 6'x6' hole to put a shutoff on and the people would be happy to pay.
 
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