Wooden Foot Bridge Plans
Learn how to build a simple beam bridge from wood for pedestrian traffic. These free DIY plans include a framing detail and step by step instructions.
Wooden Bridge Construction
This bridge spans 16′. It uses treated lumber available at most lumber stores. This simple design is easily adapted for a wide range of applications. Just know that it is difficult to say the least to span over 24′ with commonly available materials. Not only are the wooden beams hard to come by, they are heavy and difficult to work with.
Nails are the cheapest and easiest fasteners. 3 1/2″ galvanized deck nails will hold quite a load, but for this application bolts or screws are a recommended option since practically every toolbox includes a powerful cordless drill. A new generation of composite beam screws have incredible holding power and are driven home rather easily using a cordless drill. Carriage bolts have the most holding power for any fastener available for use on wood. To use them simple tack the boards into position with nails. Drill a hole where the bolt will go using a bit only slightly larger than the diameter of the shaft of the bolt. Insert the bolt through the hole and put a washer and nut on the other end. Tighten it until the round head is sunk below the surface of the wood.
Instructions for Building a Simple Wooden Foot Bridge
Lay out the post holes for a 30″ x 16′ rectangle. Drill or dig four post holes at least two feet deep and a foot in diameter. Remember this is the only thing that will hold the bridge in place in the event it comes in contact with flood water. The larger and deeper the holes are, the more resistant the foot bridge will be to flood water. Pour high strength concrete around each post. Let the concrete set over night.
Tack the 2 x 10 x 16′ bridge beams in place to the side of the outside of the posts. To beef up the design to support a little more weight use 2 x 12 for the beams. Make sure the beams are level. Saw the posts off with the top of the beams if no handrail will be used. Use 2 x 6 floor boards. Fasten them with 3 1/2″ deck nails or composite beam screws. There is no need to space the boards. In some cases it is desirable to raise the bridge quite a bit to compensate for flood conditions. If this is the case, then build steps or a ramp on each end. Use the same materials and approach.
For an optional handrail attach 2 x 4 x 16’s to the outside of the post three feet above the floor boards. Fasten a 2 x 4 post in the center from the bottom of the handrail to the outside of the beam. One handrail is better than none, but it is recommended to build them on each side.
Closing Thoughts for the Foot Bridge Project
This design is about as simple and basic as it gets. It is not intended to support the weight of large animals, heavy wheel barrows, or anything driven. It is intended to walk across. Flash floods unleash incredible amounts of energy in a short period of time. Even small drainage gullies can become dangerous raging torrents of rushing water. Do not cross such openings using bridge or any other method until the water subsides. Good luck with building your simple foot bridge using wooden beams!