A few years ago we had wood floor professionals extending power cables underneath the floor as part of an overall floor renovation.

We only recently learned that they used screw terminals which could be problematic when placed in inaccessible locations (such as under a wooden floor).

Our main concern is the fire hazard and it seems like we have two options:

  1. Open the floor and re-wire everything - that would require re-finishing the entire floor to achieve a consistent look.
  2. Install AFDD switches as mean to protect against fires.

I understand that option #1 is the best option. My question is how reliable AFDD switches are in this case? is option #2 good enough (realistically)?

  • Hello, and welcome to Home Improvement. I'm guessing this is too opinion-based for us; you might want to make this an "Is this to code?" question (adding in your location). And, you should probably take our tour so you'll know the details of contributing here. Oct 9, 2020 at 11:29
  • You may also want to define what an "AFDD" switch is, as not everyone is familiar with that acronym and indicating where in the world you are will be important because electrical code varies by country and sometimes even by region within the country. I'm guessing you're in Australia (based on your user name), but heck, that could just be your initials, so being specific will really help get you a better answer.
    – FreeMan
    Oct 9, 2020 at 11:43
  • 3
    @FreeMan AFDD = Arc Fault Detection Device (IEC equivalent to a North American AFCI) Oct 9, 2020 at 11:44

1 Answer 1


In my opinion AFCI / AFDD are not nearly as good as they ought to be, but that's another matter.

I also do not know what codes would apply in your locale but in many, even if the AFDD reduces the hazard, it does not bring you up to code, leading to problems with insurance, sale of the house, etc.

But aside from those problems, I don't believe it's a sufficient remediation. AFDDs are intended to detect the "signature" of arcing faults, that is, to recognize electrical activity in the circuit that indicates arcing is occurring. With a bad screw terminal connection, you can get a high resistance non-arcing fault, where the connection will heat up and possibly start a fire, without ever causing an arc and without ever triggering an arc detecting device.

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