On May 6, 3:43�am, wrote:
I have poured many small sidewalks and shed floors and never put
gravel under the concrete. �I want to pour a driveway section in front
of the garage and was told by a guy at the concrete company (who came
to measure the amount needed), that I need to put gravel under the
concrete. �WHY?

I should mention that I always put lots of small to medium sized rocks
under concrete to save on the amount of concrete needed. �I save all
rocks I get just for that use, and leave them get rained on to clean
them. �Any rock that will not exceed the height of the forms, goes in
there. �Because this will be driven on, I intend to put in some rebar,
which I never do on sidewalks and shed floors. �I have never had any
problems with these sidewalks cracking or substantially lifting in
winter.

I agree with the others, to drain any water that may accumulate under
the pad and possibly freeze in the winter. If you live in a warm
climate, not so much of a problem.

Since I live where it can get to 25 below, I usually will drop the pad
down about an inch from the garage floor for 2 reasons. 1. The
concrete will rise in cold temps. 2. To keep any water from entering
the garage.

Hank