Sidewalk Forms and Pouring In the Fill Materials - Videos

Step Three: Building the Sidewalk Forms and Pouring In the Fill Materials

The third video in our four-part series provides important details on creating sidewalk forms. Gather the critical tools before you begin, then follow each necessary step to create sturdy sidewalk forms.

Have these tools and materials at the work site before starting:

Tape rule
Marking pen or pencil
Wood stakes
Nails
Long level
Enough 2x6"s for the sides and ends of the sidewalk, plus one wider than the forms to use as a bridge during the pour
Expansion joint material
Saw
Shovel
String for guides
Gravel
Sand

Creating Sidewalk Forms

Follow these steps to create the forms:

Starting at the end that abuts an existing patio, porch, or step, measure and place marks on the existing structure to the width of the new sidewalk. We'll call this the "near end." The opposite end where the sidewalk terminates we'll call the "far end." Measure and drive stakes at the far end, too, straight out from the near end. Do this even if the sidewalk will curve. (See #10 - 14 below for a curve.)
Drive near end stakes into the ground so that the outside of the stakes is at the outsides of the marks on the structure.
Tie the string on the outsides of the near end stakes, because the string represents the insides of the forms you'll be creating.
Checking with a level to keep the strings perfectly horizontal, drive stakes in the ground at the far end of of the new sidewalk, to whatever width you want there, straight out from the near end. Do this even if the sidewalk will curve. (See numbers 10 to 14 below for a curve.) Tie strings tautly onto far end stakes.
Dig earth away 4" outside the taught strings to make room for the 2x6" wooden forms and stakes.
For a straight sidewalk, place a 2x6" studs on edge in the prepared bed. Drive stakes (wide sides parallel to sidewalk bed) partway in the ground outside the plank every three to four feet, and overlapping butted stud ends. Nail the first 2 x 6" to the outside of the stake at the near end. Put a stake outside, too. Keep the top of the 2x6" even with the surrounding ground.. Using the taut string as a guide, carefully keep the inside of the 2x6" forms aligned with the string before nailing.
Drive stakes (wide sides parallel to sidewalk bed) partway in the ground outside the plank every three to four feet.Place additional 2x6"s around the perimeter, cutting to fit. (If the sidewalk will curve, stop the studs at the beginning of the curve.)
Before pounding the stakes firmly into the ground, measure the distance from the level string line to the top of the 2x6". Keep a slope of about 2" per 10 lineal feet to accommodate water runoff. This is very important for safety. Now nail all stakes firmly into the studs. If your sidewalk is straight, skip to #14.
Back fill with earth and tamp behind the forms.
To measure for a curve, drive stakes in the ground at the far end in a straight line from the near end stakes. Then measure how far from the near-end stake you want the curve to begin. Cut 2x6's to end at that point.
Beginning the curve: Put a stake at right angles to the 2x6" where the curve begins. Offset the stake a bit in the direction of the curve, and nail the stake to the end of the 2x6".
To stake a curve, determine how many inches long the curve will be from the right-angle stake to the end of the curve, and how many inches the curve will turn away from the strings. For example, let's say you want the sidewalk to curve 16" to the right over a distance of three feet. Drive a stake into the ground 16" to the right of both far end stakes. These mark the "new" far end.
Measuring from where the curve begins, use your finger to mark lines in the dirt at right angles to both sidewalk edges at half of the distance of the curve. For example, for a 36" long curve the marks would be at 18". Now mark across that dirt line half the width of the curve. For a 16" curve the crosshatch mark falls at 8". Drive a stake in the ground there on both sides of the excavation, which represents the half way point of the insides of the curve.
Use bendable plywood for the curve forms. Cut 6" deep forms to the appropriate length from plywood. Stake forms both inside and out, in pairs, keeping inside stake lower than the surface by about 1-1/2". Nail a 2x6" stud at the far end of the plywood form stakes.
Tack expansion joints across the near and far ends inside the wood forms.
Pour gravel to 4" from the prepared earthen bed. Smooth with a rake.
Pour, smooth, and tamp or dampen sand 2" deep on top of gravel. You now have 4" of depth left for the concrete.