Eliminate drainage problems around your proposed deck before you build it. Some of the ground beneath the deck will be wet from time to time, but you want the areas around the foundation to be firm. If you have standing water or chronic soggy areas near the site, consult a landscaping contractor for advice on improving the drainage. If a downspout empties close to the deck, reroute it. If necessary, add a drainage ditch to divert water away from the house and deck. Be sure water drains into a dry well or municipal sewer and not into a neighbor's yard.
1. Level the grade
Install batter boards and pound stakes in place for tying guidelines to aid you in grading the site. (You'll set guidelines for the deck structure later.) Remove the sod. If the deck will be close to the ground, check for high spots in the grade that could interfere with joist placement. Smooth high spots with a rake or shovel. To ensure grass and weeds won't grow under the deck, cover the area with landscaping fabric. In addition to controlling weeds, landscaping fabric allows water to drain through it while keeping the gravel from sinking into the soil. Fasten the fabric in place with landscaping fabric staples and cover the surface with a 2- to 3-inch layer of gravel.
2. Build sawhorses
You'll need a stable work platform on which to cut your deck material. This sawhorse design is easy to build and far more sturdy than the metal-bracket and scrap-lumber types you can buy at home centers. Cut one 8-foot 2x4 in half to make the T-beam. Make the 30-inch legs from a single 10-foot 1x6. Put it together with 21/2-inch general-purpose screws.