Cordwood Arch in North Carolina

Hi, Lloyd!

Thanks for the books and blog! Such an inspiration over the years. I wanted to share with you this cordwood masonry arch I built in the spring of 2017. It’s at the North Carolina Museum of Life and Science in Durham, functioning as the entrance to a woodland playground area. I’m pretty happy with how it turned out. I thought you might appreciate it.

I’ve been fortunate to work on a few really cool projects at the museum over the years, including this arch and a series of interconnected treehouses, hideaway woods. The arch is about 24′ long by 10′ high.

The arch is built on a stone foundation. The cordwood is a mixture of southern pines and eastern red cedar. I used a lime and sand mortar with a smidge of Portland and pigment. The arch itself was no doubt the trickiest part. I did some math and made a full-scale drawing on a huge piece of cardboard to confirm that the angle of the 6×6 timbers was correct in relation to the span. It’s amazing how much the slightest change in angle of the arc components changes the span. One other thing, you can’t tell in the photo, but the arch tapers quite a bit as it rises. This keeps the center of gravity lower, making the structure more stable laterally. I consulted with friend and master stone mason Thea Alvin, about making sure the arch would be structurally sound. The taper was her suggestion.

It was my first cordwood project. Before taking it on, I’ll admit I had mixed feelings about the aesthetics and soundness of cordwood construction. But I ended up really enjoying the process, and found that with the right approach, it can look outstanding.

Thanks for sharing, Lloyd!

Truly,
Michael
Michael McDonough
Rising Earth Natural Building
Troy, NY
www.risingearthbuilding.com