Raise the Roof

By Isaac Grayson

This spring break was much less exciting than many of my classmates. I did not leave the country, lay on the beach, climb a mountain or jump off of one. My most daring move was to not look at my thesis for five whole days! Instead I took the opportunity to work on some other projects. Focusing particularly on my non-western history project and trying to get a handle on my furniture design project. For my history project I chose to build a small model of a reciprocal frame.

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                The reciprocal frame has a fuzzy history but can recently be seen making a revival in eco-communities. I have seen this sort of roof most often seated on posts with straw bale/cob infill. The roof has unique properties that allow it to not need a center support. It is also very adapt to ameba shaped floor plans. The reciprocal frame relies on a team work. Each member of the roof structure rests on its neighboring member all wrapping around so that the last piece rests on the first one.  I saw this structure first in one of Lloyd Kahn’s book that discusses vernacular architecture. 

                I found a good reference book by Olga Popovic Larsen that goes into great detail about the math needed to calculate but in this exercise I didn’t want to do the calculations. I wanted to feel the materials to mold them to be the creator and not merely the designer. I knew I was going to start with a dimensional piece of lumbar, and rip it down smaller to create something that I could carry through the door ways. After I did a rough layout of my pieces I established a perimeter to roughly keep the build within and began to stack the members. I quickly found that they were wanting to slide and twist so I had to place a nail for them to rest on and secure them with pink sting while I continued to build the revolving structure.

After I got the structure settled where I wanted it I marked the overlapping areas and numbered the boards to be able to put it back together later. Then I began to carve out the notches. For simplicity sake I only cut a notch on the top side of the members to allow myself more wiggle room to slide the pieces together. Because this is the first time doing this I did not trust my accuracy. This was a very good thing because every dry fit I did after this ended up being a little off what I had originally put together. And I had to go back and re-notch the last piece because it just wasn’t coming together correctly.

             Finally it was time to begin gluing. But after only two days of nice weather there was the threat of snow and freezing temperatures again. So it seemed in the best interest to move the project indoors and allow it to setup under more temperate conditions. With an extra set of hands the final assembly and gluing went well.  When the moment of truth came I was able to move and transport the piece all the way back to Carbondale without any mishaps. Now all I have to do is not step on it while it sits in my apartment and I wait for the due date to arrive. 

Also Check Out! The Year of Mud: Cob & Natural Building Workshops (http://www.small-scale.net/yearofmud/2008/11/26/how-to-build-a-reciprocal-roof-frame/)