My home builder gave me cat5e outlets in the wall (near the ceiling, for cameras) with just a plain white wall plate. Behind the wall plate is an open back wall box (I think), the cat5e cable and a whole lot of insulation (the pink puff balls kind that go between walls to retain heat). I replaced the wall plate with this https://www.amazon.com/gp/product/B00DL93SLU
I heard somewhere that all holes in the wall with wires/plumbing coming out should be closed with fire insulation foam. Should I get some fire foam and seal it up? Or should I replace the open back wall plate with a close box? Or do I replace the wall plate I have and install an ethernet interface?
Best Answer
For mains electrical power, you need fully enclosed boxes, to reduce chance of fires from electrical arcing.
You don't need that for low voltage wiring. An open back box or "wish box" is just fine. Weirdly, I priced the two types of box yesterday, and the "wish box" was 40% more expensive.
Do not under any circumstances fill any electrical junction box with foam.
You weren't saying you would, but somebody is going to read this and maybe think that. Anyway, most foams are fire accelerants not retarders, and it is easy for even professionals to make Very Big Mistakes in this area.
I don't like the starburst shape "gasket" either. I would install a listed wall plate receptacle so you have a proper Ethernet socket in your wall. A listed receptacle will be tested for fire safety. Amazon tends to be glutted with Cheese junk and counterfeits, so watch out.