On Jul 18, 10:06*am, Jim Elbrecht wrote:
"Edee em" wrote:
Bit of a simple question, I hope:

Nothing is ever simple.

I want to form for a 10x8' concrete pad for a shed. *The spot I want the
shed in has a bit of a slope. *I believe it to be about 4-5" over a 10' run.

That's a good pitch for starters..

The problem thus is how to build the forms to take out the slope in the
grade. *I imagine a 2x4 in the back (high end) and a 2x6 in the front (low
end) but what is the best way to get the sides to go from 4" to 6". *Of
course I may be way off in my thinking and would appreciate any other
thoughts.

If it was mine-- and I only wanted to do this job once. . . . * * I'd
scrape all the sod and crap off the site. * * Then I'd bring in a load
of #2 crushed stone for a base. * * Spread it on the site a couple
inches at a time. *Tamp well. * $75 to rent a compacter for a day is a
cheap investment. * On the upper side I'd make sure it was at least 4"
thick [8 would be nice but it might involve digging]. * * *Make it
level. * * use 2x4 to form your pad.

Once a shed is sitting on it [full of crap] is a poor time to try to
straighten up a pad that was poured on a sloppy base.

Jim

From my experience (and I'm no concrete expert) from building my forms
for my 18x22 workshop, the top of the forms have to be level at the
top. Drive two wooden stakes in each corner into the ground about 2
feet outside each corner. Each stake will be used to tie a string
line to show the inside top of each form. Tie strings from one
corner over to the adjacent corner. If done properly, all strings
should be level when done and will form the square of your proposed
slab. Once this is done, determine the distance between the string and
the ground and multiple points on each side. This will determine the
height of each form. you will need to dig a small trench 2" wide on
each side to put your lumber so that the top of the lumber is barely
touching your string. Make sure you brace the lumber with wooden
stakes on the outside, as concrete will pus the form out if
unsupported.. When everything is done, make sure the top of all the
lumber is level to each other as this will be the top of the slab.

I would also suggest following the previous suggestion about the base
preparation. a good base will keep the slab from cracking.

Rob