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The space and the goal: I have a townhouse, with a fire barrier between the units. This fire barrier wall is also where the TV is mounted, and I want to install a media box behind the TV, and then an opening lower on the wall that will be covered by a floating shelf that houses the apple TV and such. This setup will allow me to run HDMI cables and etc into the lower opening, up through the wall, and out the media box to plug in behind the TV. All wires hidden! I'd like to make the process of pushing wires through the wall easy by connecting the top and bottom openings with a 1.5-2" conduit pipe. Since the wall is a fire barrier, I know special precautions must be taken (for example, I need to use only 2-hour fire-rated boxes, as confirmed by a local inspector).

The questions:

  1. What conduit pipe should I use inside a fire barrier?
  2. What connectors should I use between this conduit pipe and the electrical boxes/openings, to be up to at least a 2-hour fire rating?
  3. Do the box covers for the electrical boxes also need to be 2-hour fire rated? (Most media boxes have plastic faces, for example this one). If so, any suggestions for recessed boxes that have 2-hour fire-rated covers?

Thanks!

Itallia
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  • I am going to leave this as a comment as it was news to me after 40 years of using metal conduits through walls for 2 hr rating recently during the remodel of a operating room the contractor was trying to get certified conduit for a 2 hour fire wall and even ridgid conduit is not listed for 2 hour firewalls. – Ed Beal Nov 14 '21 at 16:12

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The only truly legal listed method I know of to wire through a 2 hour firewall is to use metal boxes 24” apart or further. The boxes have to be tight to the Sheetrock or drywall. In the case of old work many of the boxes require a larger cutout so professionals use a thin metal piece called battleships or that’s how I order them a thin stamped metal piece you break apart cost under a dollar and slip beside the box and fold in, note you have to use a box with mud ears to keep the box from falling in the hole.

Can’t get away with a low voltage mud ring in a fire wall.

Added: I checked as slang terms like battleships may not always work in different areas but platt electric search came up with several the first battleships was DSI2A at 0.88$ In bulk cheaper, I then searched on line and there is a quick video on how to install them.

Battleships it’s only 30 seconds and what pros use to tell the truth I have never seen a DIY person use battleships.

Ed Beal
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