Thread by @JimmyRis

Cob Building:

Cob (or adobe or wichert or lots of other names) is a building material made from mixing mud, sand, and straw; cobbing is one of the oldest known building modalities thought to be used since prehistoric times.

en.wikipedia.org/wiki/Cob_(mate…

At Colab, we built a cob bench for seating around a cob oven that had been built previously. After slapping together a rough wooden frame to get started, half of the crew mixed mud and half applied it!

Cob mixture: 1 part clay-based soil, 1 part coarse sand, a good amount of straw and plenty of water

Then mix! We got our feet dirty stomping around in the mud to get it mixed completely. The kids were more than happy to help with that part 😆

We placed rocks all around the base of the bench, as it's important to keep the cob itself from contacting the ground too fully. When the ground gets moist in the winter, the clay would act as a sponge and wick water into the bench, causing it to crumble.

We piled the cob mixture on the rock barrier and packed it down, slowly shaping the bench. Because it's just piled mud, you can shape and mold the structure to whatever form you'd like, leaving lots of creative license for builders to customize their creations.

By the end of the weekend, we had a completed cob bench drying in the sun, and by Monday we were enjoying our new seating while we cranked out of pizzas from the cob oven! 🍕

Cob's big weakness is water: if it gets too wet, the mud will soften and the structure can fall apart. But linseed oil on the surface can provide some limited weather-proofing and durability.

Besides, if it falls apart, you can simply rebuild using the same material!

Our badass instructor Zeb shared a story about rebuilding a wall of a cottage in the UK that had been damaged in a heavy storm. They added water to the decades-old mud that had crumbled and built the same wall right back up where it was.

We built a simple bench, but cob can be used to create serious structures! Multi-storey houses, barns, you name it. It's cheap, sustainable, low maintenance and can be built on most zoned land up to a certain size (you'll need to check your local regulation)

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