What fire hazard considerations are there when creating a cable hole between rooms?

Question

Can't believe this hasn't been asked before, but I can't seem to find anything so...

I've currently got a very light, very thin 32" TV mounted on the bedroom wall. It's perfect - except for the fact that I'd love to make it a bit more minimalist and put the cables through the wall it's mounted on, into the fitted-cupboard in the room behind it.

In my mind, the best way of handling this is to drill a hole straight through the wall into the cupboard, reinforce it with a bit of metal piping or something, then block both ends with some sort of plastic/sponge filler.

However, I'm worried about fire safety - I've heard that if you start to play around with holes between walls, it can seriously degrade the compartmentalization of the rooms and fire can spread more easily.

Am I insane? Too cautious? Or are there serious considerations when mucking about with the integrity of 'rooms'.

Answer 1

To the best of my knowledge, the only fire retardation requirements that exist for a residence apply to slowing the spread of fire between connected units - say in a duplex or row home.

In the case of your personal dwelling, there is almost no way to restrict the spread of fire within a residence without making it extremely inconvenient to navigate in your own home.

Now if you installed fire proof doors between every room, with airtight seals (ie: like your exterior doors), and fire retardant barriers like cinder block and fire-resistant foam between the walls, then your concern over putting a hole in your wall would be relatively worth considering, but I suspect that like most homes, these other barriers do not exist on the inside of your home, and so you're worrying over something that, in the grand scale of overall fire safety, won't amount to much.

Answer 2

In a single family residence, with the exception of a garage, I don't believe there are any codes concerning the spread of fire. There are requirements to have smoke detectors to notify you of a fire, and other requirements to avoid creating a fire, but not to stop it's spread.

If there were, you'd need fire rated doors that seal to the floor between rooms, fire rated drywall separating sections of the home, spring loaded vents that automatically close to keep fire out of the HVAC ducts, etc. It is a good idea to prevent fires from going between floors by sealing around ducts and other utility lines.

This completely changes when you get into multi-family dwellings. But in that scenario, it's all about preventing a fire in one unit from spreading to another in under an hour (the typical time for fire rated drywall and doors). The hope is that the fire department puts out the fire in that time. For these builds, we have to use fire rated drywall on all common walls between units and adjacent to common areas. The ceilings also received fire rated drywall and even the attic was partitioned between the units even though homeowners didn't have access to the attic in one of our builds. Electrical boxes on common walls were enclosed in a box which was further sealed with fire rated caulk on all sides to keep the fire from spreading through the outlets. All openings between floors are sealed with special insulation or fire rated spray foam. And even the HVAC ducts have spring loaded mechanisms to close in the event of a fire.

Answer 3

As BMitch and The Evil Greebo both point out, you may not be required to seal the penetrations. However, if for your own peace of mind you wanted to do it, here is what I'd do.

• Install a single gang electrical box on each side of the wall (not back to back. And don't use low voltage boxes for this application).
• Connect the boxes using flexible metallic (or nonmetallic) conduit.
• Pull the low voltage signal cables between the boxes (remember you can't put the power cord through the wall).
• Seal the conduit openings using Duct Seal Compound.
• Install desired cover plates.