How sketchy would doing this be?

[swimmer_spe]

On a scale of 1-10, where 10 is very sketchy and 1 is not at all sketchy, how sketchy would this be to do:

I have a house built on shale rock. Part of it is a full basement, part of it is rock. There is also part of it that is gravel on top of the rock.
What I want to do is to dig out all that gravel down to about the depth needed to be close to the basement height.
Not so sketchy?
Ah, but it gets better. It is in a block framed section of the basement. That section of block wall sits on concrete. All good so far, right?
Some of the joists are sitting on posts, while most are not. All joists in that area span the same length regardless of whether a post is under it or not.
Kinda sketchy, right?
So, my plan would be to sister the joists with same sized lumber as they are as long as I can go, possibly to the block walls. This would mean those posts can be removed, right?

So, how sketchy would that be?
(Obviously bringing in an engineer to do the math and direct me would make it a zero.)

 

[bud16415]

Oh I would give it a zero, what’s the worst thing that could happen? Your house collapse with you under it.

 

[Sparky617]

I'd think some one added the posts that are under select joists to take some bounce out of the floor. Adding a beam at this point, properly supported would be a more effective method.

If you're digging out the basement, is the floor currently gravel or is there a slab? Are you going all the way out to the walls with your excavations? Keep in mind you walls likely don't go much below your floor level. So you'd need to add blocks and new footers below the wall.

How much are you looking to gain by lowering the floor? Another option would be to work with a house mover to jack the house up and add blocks or blocking between the existing wall and the floor joists. But given the information provided I can only offer ideas, not guidance on what you can or should do.

 

[swimmer_spe]

I'd think some one added the posts that are under select joists to take some bounce out of the floor. Adding a beam at this point, properly supported would be a more effective method.

If you're digging out the basement, is the floor currently gravel or is there a slab? Are you going all the way out to the walls with your excavations? Keep in mind you walls likely don't go much below your floor level. So you'd need to add blocks and new footers below the wall.

How much are you looking to gain by lowering the floor? Another option would be to work with a house mover to jack the house up and add blocks or blocking between the existing wall and the floor joists. But given the information provided I can only offer ideas, not guidance on what you can or should do.

The current part of the full basement is about 7 feet floor to ceiling. It has a concrete floor. The crawlspace is about 4 feet high at the highest part, and about 2 feet over the rock. My plan would be to dig out the loose stuff and then hire a company to come and break up the rocks and concrete that does not need to be there and to engineer the stucture to remove the interior block wall. My plan is to not dig under the existing concrete. If I get to dirt, I will put the dirt back in to stabilize it.