Low voltage wiring boxes


Active Member
My home (under construction) will be getting spray foam insulation in a month or so. I want to run some smurf tube conduit in a few exterior walls before the house is insulated. All the low voltage "boxes" I've seen that accept smurf tube adapters are open on the back and sides. My guess is I will end up with the LV boxes at least partially encapsulated in the foam, and may have some foam that expands up into the smurf tubes.

Are there any boxes that are more like the blue plastic line voltage boxes that will accept a 3/4" or 1" smurf tube adapter? I guess I can tape the tube openings to keep foam out of the tubes, but I would still have to cut out the foam around the LV boxes afterwards. I'm getting open cell spray foam, so cutting it out probably won't be too bad, but it seems like a closed box would be a lot better.

I wanted to put junction boxes on the side of my house for camera hookup. I used the blue junction box and just drilled a hole in the back, then attached blue smurf tube to it. Then foam insulated around it. The smurf tube comes out in my attic. I sealed the smurf tube with electrical putty after cat 6 wire. It worked well.

A LV box would probably work too, as the open cell foam is easy to pull out.
Be sure to run the LV cables you need outside the conduit, before the foam. Save the conduit for future cables.

Dealing with line voltage boxes and conduit for LV cables is challenging. If cutting the spray foam is easy, I’d probably go that route. With LV rings, the conduit just needs to be with an inch or 2 to use them.
I use the standard orange LV box. When its an outside wall that will be corebonded, I duct tape the back in the rough to keep the box clean. Then in the finish, I cut out the duct tape so I have as much space as I need.