rlz wrote:
On Aug 1, 1:15 pm, wrote:
Well after contemplating several options, have decided to pour a
concrete slab for 12 x 16 shed....what I have done so far is to
remove sod and put up forms. On one side the top of forms are about
4" above grade, and the other side witch is 5' from property line,
top of forms are about 10" above grade. Also I am in Michigan so
42" frost line and I do not have great drainage, but have chosen a
location that is higher. I plan to pour 4" slab.

Am thinking to dig out one side to about 6" depth and fill with
couple inches of sand..the other side will need to be filled more,
my neighbor says just fill with sand, but I think I should fill
with 4 or 5 inches of crushed limestone then inch or two of sand on
top....is this one of those 6 of one half dozen of the other type
deals?

should I put a footing around perimeter? if so how big? or would
that be overkill. and would a footing say 1' deep by 1' wide be a
problem with frost? what about just pouring concrete 6" thick at
perimeter, would that be ok?

With the drainage issues here, think I need a moisture
barrier....What should I use?

also thinking 3/8 rebar - spaced about 18" sound right?

any advise appreciated.

I recently poured a 18'x22' slab for a workshop and had a foot
difference in grade between the short ends. Our city inspectors
required the top of the slab to be 6" above grade and a foot below
grade around the parimeter. The perimeter trench had to be a minimum
of 8" in width and then sloped inward toward the center. They also
wanted #4 rebar to go inside the trench 3" from the bottom and 3"
inches from the top. Also remember to put in anchor bolts for your
wall studs when pouring the concrete to anchor your walls.

My best advice is to consult with the city inspectors if you're
required to pull a permit.

Have fun doing the job.

Robin

You cannot have too much re-rod. Don't use the #3 size, go for the 1/2" or
#4 size. I built a shed foundation, 5" slab with 16" deep stiffeners all
around. Had a source for some free re-bar and dropped 320 lineal feet into
the foundation. That was 25 years ago, not a crack in it. This is in the
Toronto area of Canada with a 48" frost line.