Forming a Concrete Pad

Intro

Many concrete patios and sidewalks are less than 2 inches thick and lack metal reinforcing. In areas with freezing winters, they will almost certainly develop cracks. These pages show how to build a long-lasting pad.

A concrete slab may be raised one step height above the yard or an adjacent patio surface, or it can be set just above ground level. If the pad is 75 square feet or smaller, you don't need to worry about drainage. To determine the location and height of a landing for the steps. The pad shown here includes two piers to key into its sloped site. Omit the piers for a level site.

Though it may feel solid a few hours after pouring, concrete takes a week or two to achieve full strength. Wait at least three days before exerting heaving pressure on the pad.

Prestart Checklist

Time
About a day to excavate, build forms, mix concrete, pour, and finish the surface

Tools
Level, tape measure, circular saw, sledgehammer, drill, hammer, wire cutters, concrete, wheelbarrow, hoe, concrete finishing tools (opposite page)

Skills
Measuring and cutting, checking for level and square, mixing in a wheelbarrow, smoothing a concrete surface

Prep
Determine the location for the pad and remove any sod

Materials
Lumber for forms and stakes, gravel, bags of dry-mix concrete, reinforcing wire mesh

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Forming and Pouring a Concrete Pad

A solid concrete pad is 4 inches thick, rests on a bed of well-tamped gravel, and is reinforced with special reinforcing wire mesh.

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Step 1

Excavate topsoil and tamp down about 2 inches of gravel. Cut 2x boards to use as forms for the pad. Fasten them together in a rectangle. Use a framing square to check the corners for square. Fasten the boards to stakes driven into the ground, and check for level and square.

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Step 2

Backfill with soil behind the form boards so wet concrete can't ooze out from the bottom. Cut wire reinforcing mesh to fit and lay it on top of stones so that it will be near the center of the pad's thickness when you pour the concrete.

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Step 3

Mix the concrete and pour it into the forms. Using a board long enough to reach from form to form, screed the surface: Drag the board, using a side-to-side motion as you move it across the length of the pad. Repeat until the surface is fairly level and has no low spots.

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Step 4

Using a wooden, steel, or magnesium float (shown below left), smooth out the entire area. With the float held nearly flat, lightly scrape across the pad in long, sweeping arcs. As you work, water will rise to the top. Keep smoothing as long as the surface is wet. Once it has started to dry, lightly drag a broom across it to create a nonslip surface.

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Step 5

Slip the point of a mason's trowel between the form and the concrete and slice all around the pad to a depth of 1 to 2 inches.

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Concrete finishing tools

These three tools are all you need to finish a small concrete pad. A magnesium float is easier to use than a steel or wooden float and is more than adequate for smoothing the concrete before giving it a broom finish.

Step 6

Run an edger around the perimeter to round off the corners. This will prevent chipping. Press lightly and repeat until the corners are smooth. Let the concrete set for a day, then pry away the forms.

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