Building an outdoor kitchen out of 4" concrete block, it will be faced with natural stone veneer.

As I'm stacking the block, I'd like to add a few electric boxes, here's the 2-1/2" deep masonry box that's made for 4" block: enter image description here

I assume the front of the box is flush with the outside of the block. But what about when the ~1" of natural stone gets added to the block, it wont' be flush anymore??

I havent' been able to find any type of plaster or tile rings that extend masonry boxes.

Please help, I'm a newbie!!


  • 1
    Hint: also buy whatever cover or faceplate you intend to use at the same time, so that you know what the final configuration will be when determining how flush it should be. I know of a situation where an in-use cover for a GFCI outlet would not fit—to fix they actually had to tear stone facia apart and reset it. An “in-use” cover is likely code required if this is a receptacle—they hadn’t planned for that, they intended a standard weatherproof cover and it failed inspection, the fix was costly.
    – Tyson
    Apr 12, 2018 at 22:33

1 Answer 1


I think you position the box sufficiently proud of the cement blocks so that the box will be flush with the intended finished wall. Err slightly on the side of having the box inset in the finished wall and if necessary use a box extender(metal) or plastic. If you use an extender, you will have to use a ground pigtail to get a robust ground connection.

  • 1
    Thanks. I think I'll get the 3.5" deep box then let it 1" extended outside the block.
    – dan
    Apr 12, 2018 at 23:53

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