Stuffing Insulation into Circuit Breaker Box Cavity

Qs Laptop

Thinks s/he gets paid by the post
Joined
Mar 11, 2018
Messages
3,554
Getting ready for another punishing winter here in Minnesota. I'm recaulking all openings where wires, cables, pipes, etc. enter the house. One particular problem spot is the circuit breaker box/cabinet in the basement. During winter I can feel cold air seeping into the room surrounding the cabinet. I will be re-caulking around the hole where the main electrical cable enters the house but I'm concerned that won't be enough to stop air getting into the house in this area.

The circuit breaker box is hidden inside a wood cabinet mounted at eye level on a wall in the basement. The main power line comes in from outside, above the actual circuit breaker box. Various romex wiring leaves the top of the circuit breaker box and goes upward into the floor joist area and then throughout the house into the rooms.

There is a cavity of open space at the top of the inside of this decorative wood cabinet that contains cold air in the winter. I'm thinking of stuffing fiberglass insulation in that cavity to mitigate the amount of air that leaks into the room.

Is there any reason I should not put insulation in this space?
 
As long as it is not inside the UL listed cabinet itself, go for it. I would do the best to caulk and seal that area first.
 
As long as it is not inside the UL listed cabinet itself, go for it. I would do the best to caulk and seal that area first.

Nope, not inside the actual box where the circuit breakers are but in the area where the "highway" of wires are that enter the circuit box.

Yes, caulking that area is job one today. But if there is still cold air getting into that wood cabinet, stuffing insulation would be my next move.
 
I would not go that route if there is any possibility that you may want to run another wire through there.
 
I've used an expanding foam sealer for odd shapes and these for outlet boxes.
71xcCP-G5OL._AC_SL1200_.jpg
 
Last edited:
Maybe the spray foam that expands - the less expanding type as the normal really expands a lot. Advantage is it blocks the air too.

I will likely be using expanding spray foam to seal the hole where the main electrical cable enters the house through the siding on the side of the house. After that has expanded and set, I will trim it flush with the siding, and then put a "donut" of duct seal around that area.

It would be near impossible to get to the hole where the main cable enters the wooden cabinet. Also, I generally don't like to use that spray expanding foam because it's hard to get rid of once it's in place, plus it's ugly to look at.
 
I've used an expanding foam sealer for odd shapes and these for outlet boxes.
71xcCP-G5OL._AC_SL1200_.jpg

Yes, I'm getting those outlet insulation covers for several outlets in the basement.

I'm also considering stuffing insulation around the electrical boxes where the outlets are housed. Any reason why I should not do this?

My house was built in 1979 and the basement is not insulated with insulation rolls between the wall studs. Instead it has foam insulation boards between the wall studs and there is plenty of air leakage around the outlets.
 
Yes, I'm getting those outlet insulation covers for several outlets in the basement.

I'm also considering stuffing insulation around the electrical boxes where the outlets are housed. Any reason why I should not do this?

My house was built in 1979 and the basement is not insulated with insulation rolls between the wall studs. Instead it has foam insulation boards between the wall studs and there is plenty of air leakage around the outlets.
Not that I'm aware of. My house already has insulation around my electrical boxes. Maybe I'm not understanding what your concern is?
 
Last edited:
Not that I'm aware of. My house already has insulation around my electrical boxes. Maybe I'm not understanding what your concern is?

I'm being ridiculously paranoid about glass insulation somehow starting on fire. Silly, I know.
 
... Is there any reason I should not put insulation in this space?
Well, it's not intended to block air flow, so any effect will be marginal. Another thing, cold air leaking into he basement by whatever path is replacing warm air leaving the house upstairs. So don't fixate just on the basement. Those "socket sealers" are intended to slow down warm air from the house as it travels through the wall cavities and out any leak points at the top of the walls. In our new house every place some Romex penetrates from a warm space to a cold space they have sealed the hole with expanding foam as a caulk. If you can get into the attic, IMO this is worth a look.
 
I'm being ridiculously paranoid about glass insulation somehow starting on fire. Silly, I know.

It's fireproof as far as I know. If I'm wrong let me know.

Is your attic already at R40 ? , that is where huge heat losses are.

I personally don't worry about cold air coming in the basement as we have a gas water heater and furnace, and they have to burn basement air. This creates a vacuum inside the house which is satisfied by air leaking in.
Better it leak into the basement than the living-room where we sit.
 
Back
Top Bottom