cob
Presentation Outline 1. 2. 3. 4.
Overview of Earth Building Examples of Cob Construction How to Build with Cob Frequently Asked Questions
1. earth building – something for everyone
wattle and daub
Mud mixture is plastered in and around an internal structure. Does not form a load bearing wall.
adobe
Mud is pre-formed and sun-dried ‘bricks’ are used in construction. This is a load bearing wall.
rammed earth
Earth is compacted in temporary forms. Creates a load bearing wall.
Cob Unbaked mud and straw provide load bearing
Similar to adobe, but the mud mixture is used while still damp. Cob forms load bearing walls, but sometimes an internal structure is used.
Attributes of Cob Construction • Insulates from temperature fluctuations. • Better insulation than stone, brick or concrete. • Organic shapes are easily formed and corners are not needed for structure to be sound. • Works better than adobe in cool, damp regions. • Insulates from sound. • Fire and wind resistant. • More earthquake resistant than adobe, but less than bamboo or steel. • Durable and democratic!
2. examples of awesome cob construction
Cob used in the construction of a bathhouse wall.
Cob allows for plastic forms and detailing in this highly functional and visually pleasing greenhouse.
3. so how do I build with cob in athens, georgia?
5. Frequently asked cob questions.
Do you ever use dung in the cob mixture? Yes. Dung helps the cob mixture bind together, and it also repels insects. (And the smell ceases to exist upon drying.)
What types of finishes are available for cob structures? • Clay, sand, straw, dung, flour paste, and lime are all materials that can be use to create a finished surface on a cob wall. • Don’t use a cement stucco– it doesn’t allow the wall to ‘breathe’ and will cause a build-up of condensation on the interior surface.
Can cob buildings be outfitted with electricity and other utilities? Yes. It is best to plan ahead and place the conduits and pipes inside the plastered area.
cob