How to Build a Concrete Arched Footbridge

Lay one of the 2-by-4s flat on its side so you can work on the 4-inch surface. Using the tape measure, find the center of the 6-foot length (3 feet in) and make a mark with the pencil.

Draw an arc with the pencil starting at the right bottom corner of the 2-by-4 and ending at the center of the top where you placed the 3-foot mark. Draw another arc starting at the left bottom corner and also ending at the center top.

Cut the arc shape from the 2-by-4 with the saw using the pencil markings as a guide. Use this first piece as a pattern to cut an identical arc from the second 2-by-4 by tracing the first piece onto the second piece and cutting it with the saw.

Stand the 2-by-4s up on their edges, parallel with each other, so that they are sitting on the flat side with the arches running along the top, about 18 inches apart.

Lay a piece of Masonite on top of the 2-by-4s. Line the 2-by-4s up beneath the Masonite, starting first on one side, aligning the sloping edge of the 2-by-4 with the edge of the Masonite and pounding a nail into it to secure it to the 2-by-4. Move along the 24-inch edge of the Masonite a few inches at a time, bending it to the curve of the arch as you go and pound in another nail. Do this until you’ve reached the end of the Masonite. You will need to cut another piece of Masonite to finish the base of your footbridge.

Measure the piece of 2 by 4 that remains to be covered by Masonite. Cut the correct size from the second piece of Masonite using the saw.

Secure the second piece of Masonite to the arch, butting it up against the first piece to eliminate the gap between the two pieces of board. Place a nail every few inches to attach it to the 2 by 4.

Attach the second 2 by 4 to the other side of the Masonite in the same manner as you did the first side, lining it up and hammering in a nail every few inches to secure the board to the 2 by 4.

Affix a strip of the adhesive drywall tape to the seam where the two pieces of Masonite meet, smoothing it out as you lay it down.

Lay the wire mesh out over the Masonite on your foot bridge and use the wire cutters to cut a piece of mesh just slightly smaller than the bridge. This does not have to be perfectly shaped or specific in size, but it should be smaller than the bridge so that it doesn’t stick out of the cement.

Mix the cement in the bucket according to the instructions on the packaging. Mix the cement a little “dry” so that it doesn’t run and you can control it more easily.

Apply the cement to the footbridge, starting at the peak and spreading it with the hand trowel out to the edges, first down one slope and then the other. The first layer you apply should be approximately 2 inches thick.

Lay the piece of wire mesh over the wet cement on your footbridge, pressing it down slightly.

Apply a second layer of cement over the wire mesh with the hand trowel. Do this in the same manner that you did the first layer, starting at the top of the arch and working first down one side, then the other, applying another 2 inch layer of cement and spreading it as evenly as possible.

Finish the sides of your bridge by smoothing them with the hand trowel, blending the edges in and applying extra cement, if necessary.

Allow the cement to dry entirely before moving your footbridge or walking on it.