asphaltdrivewaygravel
We're having our gravel driveway regraded. As of right now (it's fall) the basement floor of our side door/garage door is level with our gravel driveway. During the winter, the driveway heaves and rises and water has entered in both of those doors.
I remember the home inspector saying that having the two surfaces (basement floor & driveway) flush isn't up to code. Is there code regarding a step height, that we can refer to for this regrading? If not, what's the recommendation?
3/4 minus (21AA in US Midwest) is perfect for this application.
Hope you have some college kids around, that's nearly 2 cubic yards!
I would overdig another 6" to be able to place an edging to retain the gravel and make a clean edge.
Place the gravel in 2" "lifts" (lay down 2") and then compact with a plate vibrator. Repeat twice. Enjoy!
6" compacted will be quite solid and stable.
Update
This edging can be backfilled with dirt to grow grass. Just place it when you are 2 1/2" from the top. Its usually staked with landscape nails every 2 ft, but I'd do it every foot. I know you're not using pavers, but this will retain the edge of the gravel. You don't have to do anything with the asphalt edge, unless it is rolled over unevenly, in which case you can cut it with a masonary blade in a circular saw.
It's generically called a screen, and they range from a wooden frame with a section of metal mesh on it that you shovel mixed material on, which sorts itself by gravity, on up to a mechanized thing on the back of a tractor trailer with a bunch of conveyor belts to take in mixed material, then sort and distribute the various sizes.
Depending on your workforce and budget, you might be looking at a version that's somewhat like the one you shovel through, but sized for a skid-steer loader or larger front-end loader. The mechanical wonders are nice, but expensive, and I doubt your job is large enough for someone to haul one in and set it up, at least economically.
The small stuff goes through, the big stuff goes off the lower end.
Picture found at aggman.com, though it's off on some blog platform with a different address.
After you sort out the rock and level the sand, put down geotextile fabric to prevent the sand and rock from mixing before you put the rock back on top.
Since your comment implies that you'll have at this with a shovel, rather than renting machines or hiring someone with them, I'd suggest dividing the site into a grid so you can do a manageable section and then move to the next section.
Here is a much smaller skid-steer loader and a screen suited to it, that could be easily moved if somone in your area has something like it and wants to work:
Images from www.omhproscreen.com
Best Answer
I guess the inspector does not believe in handicap access. Aside from that, 7 3/4" is the maximum height of any step. When given the choice, I always keep the outside surface lower than the interior by about 4". This is for snow build up, just something I always did.