Ask An Expert - Cob Construction

Looks at cob construction as well as the results of a cob "shake test" to examine durability during an earthquake

Category:

Education

Tags:

• cob
• construction
• earthquake
• shake
• engineering

[mrprosale]

Thanks for the video. In Germany, there are cob houses that also use oak beams and hazelnut twigs in the middle of the wall between the cob, making it much stronger. They are calle "Fachwerk" and some are more than a 1000 years old! Youtube search "Fachwerk und Enxaimel" This technique could be incorporated into Cob construction and make it sustainably lots stronger :-)

[quiethand]

To the previous questions, a round structure as tested is likely as strong as you could design, short of doing a vault or dome, though those might have failed more catastrophically. One could also reinforce cob more to achieve better results. Straw bale would likely hold up much better if properly pinned and detailed, as the straw has far less mass (less momentum) and is nearly infinitely elastic. The reduced labor and added insulation value make it a good choice in seismic country.

[dwk49]

Good video. How much does the design play into how a cob structure stands against a severe earthquake? Would strawbale hold up any better?

[999gandalfthekid]

can you use dry weeds for straw? is good soil with clay easy to find in the pacific north west?