Cob Together Workshop

These are pictures from the June '05 Cob Together comprehensive workshop given by Jim Haim in partnership with Becky Bee / Groundworks. Jim and his partner Katie are both professional educators, and it really showed in the fine planning and dense schedule geared not toward production but toward giving participants a true immersion course in cob building. Becky Bee's vast experience and cob philosophy deepened the inspirational element of the workshop, leaving us all energized, excited, and enabled. The workshop covered cobbing, roofing, plastering, earthen flooring, straw bale construction, foundations, composting toilets, and electricity and included slide shows, tours of completed structures, a presentation from a solar contractor, quite good and generous organic mostly vegetarian meals, and lots of comraderie. The surprising group of participants came from parts as far away as Singapore, and included PhDs in mathematics and chemistry, seniors, teens, a construction worker, an author, a raptor specialist, a financial consultant, a number cruncher, and I am sure I am leaving someone out. Everyone's expectations seem to have been far exceeded by the workshop. To sign up for a Cob Together workshop, click here. You may also join the workshop Yahoo Group here. All pictures on this page can be enlarged by clicking.

Basics

Floor Plan
Site
Stem Wall over
Gravel Trench
The foundation of the building is a drained gravel trench. The floor is made of a fairly dry, tight cob mix over a few inches of gravel to prevent any moisture wicking from the ground. Later a finer earthen flooring will be applied and coated five times with linseed oil.

The Clay
The Sand


The Straw

 Cob is clay, sand, and straw.

Tools


Tools
Thumbs 		Need for tools is minimal. The level with a long wedge attached for
graded walls is important. With cob, it is important to start wider at the bottom and narrow toward the top. See the Cob Builder's Handbook for the formula. This cottage has plumb inner walls and graded outside walls.

Roof

Building the roof structure first (this one shown covered with tarps) keeps the cob dry and provides shade for hardworking cobbers.

Lines

Water
Water


Electricity:
The lines are cobbed
w/out conduit.
No need for conduit. Cob seems to preserve anything imbedded in it.
Vent from composting toilet still exposed. The vent will make use of a computer fan triggered by lifting the toilet lid for an odorless bathroom.
    

Site Support Facilities

Kitchen
Site Water Tank
Solar Siphoning
Water Heater
Water Heater
Close-Up


Jim Haim & Becky
Bee w/the Geodesic
Tent Library
Composting outhouse. Stinky, but better than wasting gallons of clean water every time. No need for a sceptic system, either. Just keep the flies out of the poop.
Active solar panel for charging our cameras, running the slide show, and recharging laptops. The panels are expensive, but they last forever. Your great grandkids will be willing these babies to their kids.		  

Working with and Mixing Cob

Mixing
Mixing
Mixing
Use the tarp to fold the mix over on itself. Two people can mix back-to-back holding hands to keep their backs straight. Becky says use
your heels for more
power! When

Mixing
Mixing


Mixing

When it is mixed, it is supposed to look like... well, a big turd when you fold it over. Unfortunately, I don't have a picture of the final loaf.

Jim Haim applies, integrates, and trims. Integration is the process of "sewing" a new layer of cob to the layer beneath, which is accomplished by pushing sticks (thumbs) through the cob, thereby forcing straw from the upper layer into the lower. Note custom cob saw for trimming.
     

Becky Bee at Work
     

Plastering
Earthen plaster is made of a more finely sifted mixture of sand, clay, and straw with wheat paste added. It is applied by hand, then smoothed with a trowel.
       

Cobbers at Work
       
 

Light Straw Clay
Light straw clay is made with clay slip with a goopy consistency. Apply it to straw like salad dressing. Mix, then ram it into enclosed areas for infill and insulation. Can be used as infill for joist walls. It retains its form instantly, so, if you are working with forms, there is no need to wait for it to dry.

Covering
Cover and pit the top of your cob wall to prepare it and keep it moist for the next day, making it easy to integrate new layers with the old. Note moistened burlap sacks.

Cob Ovens
There's really nothing like a pizza cooked in a wood-burning cob oven.

Experimental Earthen Floor over Linoleum
  The cottage was not ready for an earthen floor, so the Haim family let us try one on their linoleum laundry room floor. Earthen floors are made with the same ingredients as cob, but the sand, clay, and even the straw is sifted finer than that which is used in cob. When dry, the floor will have five coats of linseed oil applied.

Sculptural Details and Arches

Sun Window
Sun Window
(Inside View)
Protective Bird
Healing Arch

Imbedded Creek
Stone
Arch Form
Arched Shelves

Scaffolding
As the walls get higher, stand on either one or two straw bales. If two feel unstable, place two boards between them, or place two on the lower level and one on the top level. Supports for lumber scaffolding can be cobbed into the wall, and later driven out with a sledge hammer when no longer needed. The remaining holes are filled with cob.

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