Mook,
Would it be fine if the grass formed a little hill with this slab
on top? Never pour concrete on grass. Remove sod as required.
Use gravel, fill sand, broken cement blocks, old bricks, rocks, or
select fill (compactable sand/gravel). Set a 2x4 edge form at the
height and slope that you want to end up with. Pack the bottom
edge with dirt or whatever so the concrete can't run out. Pour
and finish. Strip forms and add back top soil and sod.

If you want it high above the grass with nicely finished 6-8"
face. Set an edge form (2x8?) around the intended slab. You
still need to have removed the sod. Raise as much of the center
with rubble or select fill as possible, leaving the top and sides
at least 2" thick. Think about the finished concrete looking a
bit like an upside down cake pan.

______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"mook Johnson" wrote in message
...
OK teach me something about slab building as I am a rookie.

The object is a 500bs box that is 2' x 4'. It is fairly evenly
distributed over the box so load is not a problem.

Like I said in a previous post I'd like the surface of the slab
to be 5" - 6" above the current ground level. This is in south
texas so frost line is not a major problem.

how would you recommend constructing this slab?


"dpb" wrote in message
oups.com...

mook Johnson wrote:
I'm going to be pouring a 3 x 5 slab 8" thick. 2" below ground
and 6" above.
It will need to support about 500lbs.

I'll be using quikrete for this. Do you think I'll need rebar
for this
small slab?

I'm w/ Dan--why in the world use an 8" pour for such a small
load?
What is the footprint of the object(s) to be mounted on the
slab? If
the purpose of the thickness is to get the height above
surrounding
grade, I'd recommend strongly considering accomplishing that by
grade
adjustment and a resulting thinner slab. A standard nominal 4"
slab
would easily support the load unless it is a very small
footprint (and
in that case it would make a lot more sense to make local
mounting
piers thicker rather than the whole slab).

As for the bar, I wouldn't worry about bar, but I'd probably
use 6"
square mesh just for doing it (and because I've got a roll
remnant
around ).

HTH, and better or more specific answers would undoubtedly be
forthcoming w/ some more info on what the objective actually
is...

BTW, iirc (and I think I do) the 80-lb Quikrete sack is 2/3
cu-ft so
your proposal would be a roughly 3x5x(2/3) cu-ft * (3/2)
bags/cu-ft --
15 bags. That's a lot of hand mixing considering the time
element
since you presumably want a continuous pour.