Homeowners want a footbridge to help them cross a deep ravine on their property. When the area is dry, crossing the gulley at the bottom requires a hop, but rains and runoff can add slippery banks and rushing water as additional obstacles. Consequently, the bridge will be high enough to avoid the steep banks and any flowing water. Built of laminated four-by-six support beams, pre-cut posts, decking and side rails, the 12-foot length of bridge will span the gulley resting on heavy block piers.
Use shovels and hand tools to level areas at the four corners of the bridge for supporting concrete blocks/piers. Position and level the first two piers at one end of the bridge using a bullet level and a bar level.
Clamp 12-foot planks to the first two piers, ensure they are parallel and mark the other ends as locations for a second pair of piers. Level the ground, position and level the piers, and temporarily clamp them to the planks.
Apply construction adhesive to a 12-foot two-by-six plank and clamp another on top. Pre-drill for carriage bolts every 24 inches, inject silicon into the holes, drive in bolts, and secure them with washers and nuts on the opposite side. Repeat.
Position footbridge beams on piers and drill holes into the wood through the metal strap on each pier. Add silicon to each hole, drive in a carriage bolt, and secure it with washers and nuts tightened with a socket wrench.
Temporarily clamp pre-purchased railing posts in position along the footbridge. Pre-drill holes, add silicon waterproofing, hammer in the bolts, and secure with washers and nuts.
Measure the distance between the outer edges of the two beams for tread length and add two inches for overhang. Center the first tread across the end of the beams, pre-drill holes, and drive in rust-resistant deck screws.
Use a speed-square to mark cut lines on planks that butt into railing posts and notch them with a jigsaw. Space all planks 1/2 inch apart, pre-drilling and securing each while working across the bridge span.
Use a paint brush to liberally coat the cut ends of the deck treads with wood preservative to prevent moisture from promoting wood rot. Walk on the bridge to test its sturdiness and balance.
Position and clamp a handrail to the railing posts and secure it with rust-resistant screws. Repeat this process for the other side of the trail bridge to complete the project.
We welcome your ideas and suggestions. Read through comments from other readers or leave your own.
Hi Ron,
I have the same question as Tung listed above.
Can we use the same design to build a longer bridge (say 20 feet)? Like him, I need is 25-30 feet, is there an easy and strong way to connect two 20’ planks together?
I was thinking I could overlap them by around 5 feet and lag bolt them.
This is for a foot bridge to cross a creek to access a pond for fishing.
Thanks for your help.
Thank you, This is a grate video. I was wondering why you didn’t put a bottom foot rail. I could see the dry wash wasn’t very deep but a rail 3 inches up off the walking planks would’ve been proper.
This video makes it seem so easy! I have the same basic question as Tung. My creek bridge needs to span 20’. Can I laminate two 4 x 6 x 20s into 20’ beams and get the same sturdy design?
Great!! Thank you Ron!
Can we use the same design to build a longer bridge (say 20 feet)? If the bridge I need is 25-30 feet, is there an easy and strong way to connect two 20’ planks together? The maximum size of the planks that I could find anywhere in Hawaii is 20 feet. Thank you in advance for your help.
Warm aloha,
Tung
Can someone send me the supply list for this bridge project? Myself and a few others are looking to build one as a commemorative structure to a mentor, surrounded by a stone peace garden. Thanks!
can a lawn tracker go over these ok?
thank you soooo much! I have been struggling to build a bridge. this is great and easy to do. ![]()
Nice robust design,
wanted to share a roof truss building trick form the wilds of W.Va.
add a layer of Aluminum flashing glued inbetween the boards.
due to the Shear strength of the metal it becomes very rigid.
Mr steve
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nice job make sure you crown your boards up