Check your local building codes:

Your project may require a gravel base, a certain minimum thickness, a storm drainage plan, reinforcing bars and wire, or several other construction considerations. Your county building department can provide you with a list of their requirements, or point you to the proper resource for advice in your area.

Grade the work area:

Begin by preparing the ground in the work area. It's necessary to smooth or excavate the horizontal surface gradient of the area. Contractors refer to this process as "grading."

Your local building codes will vary, but a good rule of thumb is to grade for at least a four-inch thick walkway slab with the top surface at about two inches above the final ground level. You'll want your walkway to be at least five-feet wide to accommodate wheelchairs. Consult your local building inspection department to be sure.

Buy your forming material:

Most projects will require concrete form boards or a special pre-oiled plywood product known as "plyform." You'll also need several form support stakes to prevent the form lumber from bulging outward when the heavy concrete is poured.

Many contractors choose an inexpensive rough board to form their walkways. Power Building Products carries mill-run pine and spruce for this purpose, in sizes from 1x4 up to 1x8, in lengths of 16'.

An inexpensive (but strong and flexible) Masonite-type siding can also be used for concrete forming, especially when it's necessary to sharply curve the edges of your form. Power stocks 7/16"-thick by 16'-long smooth lap boards in heights of 6" and 12".

Build the form:

A number of wooden stakes will be needed to support the outside edges of form. The actual number of stakes needed will depend upon the height of the form, the severity of the curves, and the thickness of the form boards, but a good rule of thumb is one stake for every three linear feet of form - minimum. Use two-by-four scrap lumber or buy pre-cut grading stakes. Stretch a length of twine to mark the location of the form boards and support stakes. An inexpensive string level is invaluable.

The support stakes should be driven into the ground along the outside of the form so they're slightly below the top of the form boards, or it'll be difficult to finish the surface of the concrete. Attach the form to the stakes from the outside using double-headed nails and it'll be easier to use a claw hammer to remove them later.

Level the top of the form boards:

Start at the highest point of the grade with your form-boards and work downhill. Plan to slope gently downhill away from structures to facilitate drainage - about a quarter-inch of fall per foot is standard for many areas. Your eye will think it's perfectly level later.

Concern yourself only with the tops of the form-boards. You can use a shovel later and backfill the bottom of the form with dirt to remove any gaps.

Better results may be achieved if the wooden form boards are coated with oil or soaked with a water hose before the concrete is poured. The boards will not wick water away from the concrete, and the edges will be cleaner and stronger.

Transition to another structure appropriately:

You'll need to install expansion joints where your concrete abuts another structure, such as another sidewalk, building, or curb. Power Building Products stocks 1/2-inch thick rubberized expansion material in 4"x10" strips.

Pouring the concrete:

Take all necessary safety precautions. Concrete can burn the skin and eyes. Use goggles, gloves, and rubber boots. Wear long pants and long sleeves. Cover your clothing with disposable and inexpensive coveralls.

A special tool is used to "float" the surface of the concrete as its poured. Power sells a tool called a "bull float ," or you may use a length of two-by-four as a float for narrow walks. "Walk" the two-by-four down the length of the pour in a rapid side-to-side motion, allowing the board to rest along the top edge of the parallel form boards. Small jobs may be completed with an inexpensive trowel, but a float provides better results for most handymen.

Finish the concrete:

After floating (but before the concrete is set) it's safer to "broom" the top to remove the slick surface and prevent slips and falls later. Use a concrete or a street broom with gentle pressure to create a textured surface.

Prevent future cracking:

You may choose to cut contraction joints in your finished walk to reduce the stress caused by the normal shrinkage of your concrete slab and reduce the possibility of cracking. It's common (and more attractive) to space the contraction joints about the same as the width of the walk.

A chalk line and a rented concrete saw with a water-cooled diamond blade will make the job easier. Cut the slots to a depth of about one-fourth of the thickness of the concrete. A four-inch thick walk will need contraction joints at least one-inch deep, or they won't be functional.