filing in an inspection pit

[joninc]

hot tub?

[Nick Sevilla]

Musician Motivational Pit?

Filled with water and piranhas, to ensure recording quality of all your projects.

(^^^)

<(((">

[jhbrandt]

Crushed rock with a slab poured over it should do the trick. If the rest of the floor is concrete, make sure you dowel the opening around the inspection pit to the new slab. You can drill holes for bits of rebar into the sides of the opening and tether the new pad's rebar to it.
I have to agree that it's too bad that the pit can't be made into something more useful. Worst control room ever? Inconvenient mic locker? I'm sure we could all think of something.

+1
All jokes aside, that's probably best for your situation.

Cheers,
John

[Snarl 12/8]

What about going the opposite way from what the Goose said and make a section of floor that's decoupled from the rest? It would be a good place to put kick drums and amps and not have them rumble other gear and mics.

[goose134]

I'm intrigued by this ^^. Let's say you fill the recess as I have described but left some sort of "floating level between the crushed rock and the new pad. I suspect that the pad would have to at least double in thickness, but you could have a flexible border between the new pad and the old floor.

There is sure to be a difference in settling between the pads. I'd totally recommend getting a really good concrete guy involved.

I will say this: For very large buildings, there are expansion joints that allow the movement of settling, swaying and such. This idea would not be without precedent.