The cob greenhouse was great; everyone loved the little hut in our yard. But it had two serious problems:
- No matter how many windows were opened, it was too hot in the summer. Cob has tremendous thermal mass. Plants would cook in there; so we mostly used it for spring starts and storage.
- It took up a lot of room in the yard, which cut down on space to gather with friends.
One evening, two or three years after building the greenhouse, I was suddenly struck with a vision of how to re-imagine the greenhouse as a community gathering space.The crux of my plan was to re-use as much of the existing materials and brick footprint as possible, but to turn it into a large horseshoe-shaped, covered bench. I struggled to explain to my wife what I was thinking; and to her great credit, she said “I’m not really sure what you’re talking about, but just do it.”
I needed a bit of extra lumber to frame the new structure – in particular, 14-foot 2×6 cross-beams, and 4×4 posts. The rest of the wood was salvaged.
Thus supplied, I began the process of deconstructing the cob greenhouse.
Halfway through, I took a break to dig postholes at the outside-corners. I cut and positioned the 4×4 posts, such that the northern posts were 8′ tall and the southern posts were 6.5′ tall (from ground level). I temporarily screwed cross-beams on to ensure the correct sizing and square form.
From there, it was a matter of removing the rest of the cob (and strawbales) to a level about 18″ above ground level, and finalizing the framing. My plan was to keep cob as the interior foundation, such that it would still be covered and protected from rain.
Lumber was attached the 4×4 posts with hefty lag screws. I then framed the interior parts that would become the 24″-wide benches with 2x4s, embedded in cob. The cob was easy to re-shape; just add a bit of water and squish into the new form!
And then, it was just a matter of finishing touches; adding slate tiles to the floor (over the gravel)…
…caulking cracks, giving the wood many coats of oil-based polyurethane, and then buying some cushions (which were promptly claimed by the cat).