Drywall opening size? [around electrical box]


Old 05-20-05, 11:05 PM
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Location: Tujunga, CA, USA
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Drywall opening size? [around electrical box]

Is there a code or best practice as to how close drywall should be to a box. I am not referring to the depth of the box. Rather how close the drywall is to the side of the box or plaster ring. I thought I heard that it should be less than 1/8" away. But that may be for the ears on switches and plugs.

I have a couple ceiling boxes where the fixture's canopy covers the hole. But, the drywall is not close to the plaster ring. In one case, the ceiling had been dropped down and new drywall installed. They did nothing with the box.The hole in the drywall was big enough that I was able to slip in a box extension and then a 3/4" fixture ring and get it close to the finished surface.

Here are some picture of the boxes. I am wondering if I must patch the drywall or is it Ok to have the fixtures canopy cover up the mess.

By the way, all of the wires in these boxes are going or gone.
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Old 05-21-05, 06:43 AM
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Phil H,

As far as the electrical goes I believe the issue is bringing the box depth up to flush so your extentions have done that but I am not aware of anything that pertains to bringing the Sheetrock or Plaster up to the box if the fixture will cover this portion you should be fine.

I will look into this more but the real issue is BOX depth mainly and you have succeeded in getting that taken care of in regards to the depth of the boxes.

I will again look at this more because I am on the road right now working on a job about 60 miles away and will be able to look more indepth into it once I am back......others here may chime in and be able to assist you more but I am not aware of it in regards to the electrical portion except to the extent you have already solved.
Old 05-21-05, 10:20 AM
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The opening size can only be 1/8" inch greater on all sides than the box dimensions. The Code would require a gap larger than that to be repaired.
Old 05-21-05, 01:11 PM
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Thanks ElectricMan and pcboss,

Do you know if i is a building code or electric code issue? I am just curious. I can see how sealing up the gap will act as a draft stop or fire stop. But, I know boxes can also be left exposed (garages etc). It seems like the rotozips / spiral saws would have a little smaller bit. The 1/8" bit does not give them any wiggle room. But I guess it is easy enough to mud or caulk the gaps which would seal some drafts.
Old 05-21-05, 01:59 PM
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It's an electrical code. You don't want any sparks from the electrical box to get inside the wall where it can ignite framing members.
Old 05-22-05, 10:33 PM
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Thanks John
That makes sense. Just the workmanship bothered me to leave it that way. Now, I know it must be fixed rather than be deferred.

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