I got a generator installed yesterday and noticed the caulking needs to be replaced around the meter box. The transfer switch was installed so close to the meter I have no idea how to strip and re-caulk.

If I ask the installer to help they will say the meter box wasn't part of the install. What should I do?

Additional concern is how can I determine if the conduit going into the house was properly sealed?

What type of caulk would you guys recommend for sealing exterior surfaces?

**breaker box is at the bottom of the pic list

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installer caulked where the red line is caulked where the red line is

caulking is peeling away from the wall around the meter box enter image description here

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  • Did the installer say why the bottom half of the left side of the new box, next to the meter box, is not caulked even though the upper half is?
    – Armand
    Nov 12, 2022 at 19:21
  • don't worry about it, brick isn't waterproof.
    – Jasen
    Nov 12, 2022 at 20:00
  • @Armand - because you can't stick the gun in there and half way is fine. Or at least better than the whole thing; the bottom should be able to weep.
    – Mazura
    Nov 12, 2022 at 23:30
  • Caulking as an NEC Code? Really? "Caulking is NOT code, but it's what the manufacturer demands for their liability issues. Furthermore, the manufacturer does not give specific instructions on where to caulk and what type of caulk to use, so there is a hole in their instructions." Caulking is NOT code [citation needed]
    – Mazura
    Nov 12, 2022 at 23:30

1 Answer 1


Use A polyester caulk such as Vulkem. Is is the preferred caulk of professionals doing exterior caulking in Florida where the weather is wet and humid most of the time. You most likely will not be able to get it between the boxes, however under normal conditions it is not likely much rain can get there. What can will run down between the box and the wall and exit the bottom. That is the reason the bottom is not caulked. You could bridge the gap between the boxes at the top with a strip of backer rod and caulk over that. Then any water running down the wall or side of the box will not run into the gap. You will have to ask the electrician that installed the box if the conduit was sealed. Even if it wasn't this is not usually a problem.

  • Vulkem has all sorts of warnings so you know it's good stuff (California doesn't like it at all). But w/e, "this is not usually a problem" +1. If it's rated for outdoor then it's fine. Water ingress into the house is the problem, assuming it's actually a problem
    – Mazura
    Nov 12, 2022 at 23:29
  • Thanks guys. I am in Houston so similar conditions to FL. I'll go down to Home Depot and get that Vulkem tomorrow. Does it come in clear? If not, I'll get the gray. My main concern is water running down the wall behind the boxes and into the house where the conduit tube is. Problem is, I saw this too late after the transfer switch box was mounted on the wall. I asked the electrician if the conduit was sealed and he showed me some fired rating caulking he used.
    – amrog
    Nov 13, 2022 at 1:38

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