Building The Bridge
Building The Bridge One of the grandest and biggest projects I took on was the creation of a new bridge in the backyard of my grandmother’s house. There was an existing footbridge that spanned over the brook, the other side was a small patch of grass to mow and a good spot to drop off leaves and trimmings.
The old bridge was beyond repair. At least 50 years old. It was interesting how it was built. The old beams and foundation were telephone poles spanning across the way. Everything was rotting. A few small time repairs were added over the years. The railings were an addition. It all had to go and begin new work and construction.
I had a blast with this project, from the start to the finished product. The first thing was to get approval for a budget and the design. I spent time on Sketchup, a design program, to 3D model was I imagined the new bridge would look like. I knew I wanted the minimum width to accommodate a push lawn mower. I was going to use regular 2x pressure treated wood. I researched many bridges and their designs. My inspiration came from the US Forestry Service and the bridges they build out in the wild and national parks. Practical designs and limited of what materials and machines they can bring out there.
This is helpful as my resources are limited and I have to be mindful of how much I am spending and stick to the budget. Another realization I made was I had many questions in regards to the technical. What size screws? What hardware? The spacing of the joists for load? I found a document that made me realize I have several similarities to a deck. Same materials. Different purpose. It’s a matter of what the final product is doing.
My bridge dimensions were 20 ft. length and 4 ft. width. We started by removing and demolishing the old bridge. I saved the old wood, thinking ahead of what I could use the decking boards for. A bench or outdoor furniture. Each stage was a process to follow. I had help from my Uncle throughout. My grandmother was the supervisor, always checking in on us and making sure we are on schedule.
After we cleared the area, materials were ordered and arrived. The date and timing was perfect. It was March 2020. Right before the shutdown and we could not go anywhere. I had everything I needed to get going for a long time. The next step was the foundation. I had my big pile of concrete bags and made the form on both sides of the brook. Mixing many bags of concrete makes is exhausting. We had to work in a hurry as everything was mixed in the wheelbarrow and the set time was short.
After the concrete cured, we could work on the span and the beams. I debated how I wanted to approach building this section. Do I use metal I beams? LVL wood? I settled on 10x20ft boards, glued and screwed together 3 times on either side. A total of 6 boards. Another task that is time sensitive, as the glue sets up in a short time and I have to go up and down the length of the beams to make sure everything is clamped together with good pressure and I have it all lined up.
As each progress point was made, I took a minute to step back and enjoy the process. Everyday there was something to look forward to doing, working with my hands, and being outside. My grandmother would watch for hours as I worked and was excited to see a new bridge go up in her backyard. Food had the extra element of tasting good after many hours of work and I slept great at the end of each day.
Seeing your idea and creation come alive and being built has a great satisfaction element to it and doing the work yourself. This was a big project for me and I was building a 50 year bridge. My father looked at it and said you built a tank. I laughed and took the compliment.
Moving on, the beams were set and installed, and to support the beams I had horizontal joists to stiffen the structure and help with shear. The old test is always pushing it with your hands and not a single budge. Good enough for me. The decking was next to lay down and this part was super exciting. Progress can take time and be slow. Once the decking goes down, the structure comes alive and ready to walk on! It’s a big milestone and is usable at this point. An easy way for spacing is a nail between boards. That way water can shed, or your speed square can go between and the lip on the square keeps it from falling through.
Now I can walk across! Before, if I wanted to move back and forth between both sides of the brook to build the bridge, I’d have to step in the water a million times. My feet and boots were getting soaked! It was nice to walk across. I was not done yet. I wanted a railing, my grandmother and anyone else could fall in, it was needed. One element of the railing was either horizontal or vertical slats across the span. I opted for thin metal wire, to maximize looking through the bridge, I wanted the beauty of the brook not be obstructed. I had several rows of the wire and I liked the idea as I’ve seen it before when near the ocean.
There was a gap between the dirt and the first step onto the bridge. We found small rock and filled a ramp to walk on. We used the old telephone poles as landscaping nearby, as the foundation was pretty steep and we wanted to prevent erosion as long as possible.
Many lessons were learned throughout the build process. Making clean cuts with the saw, tricks to save time, working alone and how useful a wheelbarrow is. The original plan for the bridge was for humans to get across, an added bonus it was an animal bridge with many critters, deer, beavers, foxes, squirrels, all in need of making it to the other side.