Regular 4 square vs masonry boxes for concrete

[JoeNorm]

Is a regular 4 square box rated to be embedded into concrete? Are the masonry boxes just stronger?

If I wanted to extend a masonry box, like I can with a variety of mud rings, how would I do so? Can you adapted them to round boxes?

To me, using the 4sqare seems easier due to the variety of mud rings available but I have not done much work in concrete.

This particular job will have cast in place boxes that are flush with concrete, then the wall will get a stone veneer so the box will need to be extended?

 

[infinity]

You can use either type. Since you need to extend a square box with a mud cover might be a better option.

 

[Eddie702]

With stone veneer which is nonconductive why would the box need to be extended?

 

[infinity]

With stone veneer which is nonconductive why would the box need to be extended?

Is it more than 1/4" thick?

 

[Rick 0920]

If it's cinder block, I use 4" squares w/ 1 1/4" rise rings. If the walls are poured solid, I use masonry boxes with a short piece of 1/4" allthread. I drill a 1/4" hole in the form board and use a fender washer and hex nut to draw the box tight to the form. Then after they pull the forms off, a couple turns with Channellocks and the piece of allthread comes right out and your box is flush with the wall. Just make sure on both applications that you run your ground screw all the way in so it creates a void in the concrete to bond your box.