Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

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?

share|improve this question
Check out the 'big walley' system of lathe and plaster repair... – Bryce Aug 11 '12 at 5:44
up vote 2 down vote accepted

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

box extender

share|improve this answer
very cool. Do you know if it's OK per the NEC to put a non-metallic extender on top of a metal box? – Justin Grant 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
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
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 posting your answer, you agree to the privacy policy and terms of service.

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