Things You'll Need
4 pier blocks with 4-inch straps, 12-by-12 inches
2 pressure-treated wood posts, 4-by-4 inches, length determined by the bridge design
4 bolts, nuts and washers, 1/2 inch, 4 1/2 inches long
2-by-4 inch boards, number and length determined by the bridge design
Deck screws, 3 inches long
2-by-6 inch deck boards, number and length determined by the bridge design
2 1/2 inch deck screws
A little ditch running through the property can help drain water during rainy periods, but can be a nuisance when access to the other side is necessary. A simple wood footbridge is a practical and fairly inexpensive solution.
Determine the length and width of the bridge.
Shovel and level the areas where the bridge will land.
Set two pier blocks on each side of the ditch so that the straps are spaced to the width of the bridge. Position the blocks so the straps are perpendicular to the ditch and the blocks are positioned directly across from each other and level.
Set the two posts between the straps on each side of the ditch. Adjust to make sure the posts are parallel to each other and level. Bolt the posts to the straps.
Screw the 2-by-4 inch boards across the top of the posts using the 3-inch deck screws. Space the boards 2 feet apart and use two screws on each side.
Screw the deck boards to the 2-by-4 inch boards lengthwise from one side of the ditch to the other, using the 2 1/2-inch deck screws. Space the deck boards about 3/8 inch apart and use two screws per connection.
Keep the landings about 2 feet back from the ditch edges. Use a string line level to level the pier blocks from one side of the ditch to the other.
This footbridge as described should not be more than 10 to 12 feet long and 2 feet wide. Any bridge can be unstable in flood conditions.