Is there an octagonal box extender that's slimmer than 1 1/2" deep? So far I haven't been able to find one.

Here's why: to cover up 30 years of patching on one of my plaster and lath ceilings, I'm considering covering the entire ceiling with 3/8" drywall, but that solution will leave two electrical boxes sunken into the new ceiling. I could re-mount the boxes deeper into the ceiling and use a 1 1/2" box extender, or I could replace my boxes with deeper ones, but it'd be easier if I could just affix a slim box extender and be done with the job.

Does anyone make a skinny box extender?

  • Check out the 'big walley' system of lathe and plaster repair...
    – Bryce
    Aug 11 '12 at 5:44

This appears to be a 1/2 inch extender that fits octagonal boxes:

box extender

  • 1
    very cool. Do you know if it's OK per the NEC to put a non-metallic extender on top of a metal box? Aug 9 '12 at 21:48
  • Is this a metallic sheathed cable system (sometimes called BX) or is it non-metallic (sometimes called Romex)? If non-metallic, I don't think the composition of the boxes or extenders have any bearing. If it is metallic cable DO NOT USE ANYTHING BUT METAL. BX type systems rely on the box itself for ground and you need actual metal to metal contact. Not certain of exactly what code says and welcome weigh in from the community.
    – bib
    Aug 9 '12 at 21:56
  • 1
    I don't believe the NEC still allows the metal armor to be used as ground in BX/AC; modern installations require a dedicated ground wire. Maybe someone with a NEC reference handy and confirm?
    – Steven
    Aug 10 '12 at 13:32
  • My concern is an old system that did use the armor as ground. Very common in older cities such as NYC. Still, good to check the code.
    – bib
    Aug 10 '12 at 13:44
  • 3
    If the metal box is grounded (through whichever means), you can add a plastic extender as long as you ground the fixture to the box. Most light fixtures nowadays have a ground terminal, so as long as you tie that into the circuits ground (which should be bonded to the metal box anyway) you should be fine.
    – Tester101
    Aug 10 '12 at 14:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.