Right way to mount a light fixture box

Old 01-10-18, 02:09 PM
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Question Right way to mount a light fixture box

I am stealing the below picture from another forum but it describes exactly what I wanted to ask. Basically does a light fixture box have to be mount between joists using those brackets that mount to the joists on each side OR can It be mounted on one side of a joist?

Furthermore, is there restriction on how close it has to be to the edge of the joist?

Lastly, can it be screwed directly under the joist (on its 1 1/2 wide side)? This scenario is not on the picture.

Old 01-10-18, 09:04 PM
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Looks like they stole the picture back since it's not here.

There is no restriction on type of box used for a ceiling light other than how much weight it needs to support. If the box is directly centered under a floor joist.... you can use a pancake box. The box screws in to the wood and sits flush with the sheetrock. Comes in standard, heavy duty and plastic type saddle.

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The bar box you described is usually installed before sheet rocking. If you are hanging a very heavy light then you can use a fan bar box. It gets installed from the ceiling below thru the hole.

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There are other types of heavy duty boxes that can be attached to the side of a joist from the hole below.

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Old 01-12-18, 08:37 AM
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It just depends on where the fixture is desired and what is available to support a box. Each type of box is needed depending on the framing.

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