On Friday, July 31, 2020 at 6:40:30 AM UTC-4, Hawk wrote:
On 7/31/2020 4:39 AM, wrote:
I just had a a question. Do I need a lot of gravel under concrete for my driveway. I live in California and get no extreme weather changes and I know this can matter in the long run. I have a guy putting concrete in our driveway, which is on a slope, used minimal gravel and rebar. Should this matter? Or should there be more gravel? Please help. Thank you



The minimum is 4" for a common driveway, but for heavier vehicles or a
"sloped" driveway, up to 12" may be necessary.

Depending on your sloped driveway, I would use a minimum of 6" and a max
of 12".

The most important thing is you need a stabilized base. That means you
can't pour concrete over soil, you need something solid. If there is
16" of soil, then packed gravel and clay, then the 16" of soil needs to
be taken out and backfilled with gravel or similar fill material and compacted.
If you only have 6" of soil before you hit a sturdy, packed formation,
then you only need 6". So how much you need depends on the local soil
formation.