Materials We Used and Their Relative Costs

The process of building a cob oven requires a lot of planning. One of the most important aspects is the budget. Our Materials and Costs team created an extensive log of all the products that go into a cob oven. Here are their findings:


  • Clay (8-12 gal):  one of the main components in cob mixture.  The abundance of clay makes it a very cheap yet appropriate ingredient for our cob oven (Wolok, 2008).
  • Sand (30-40 gal):  sand is used to fill the oven’s base and, when needed, to be added to the cob mixture.
  • Straw (1 bale):  another main ingredient of cob, straw is used as a binder to keep the sand and clay together (Payton, 2003).
  • Red Brick (enough to construct base):  used to provide a base that is supportive and can insulate the oven.
  • Fire Brick (enough to create a cooking surface):  fire bricks are able to withstand the high temperatures the cob oven will endure throughout many baking processes.  Red bricks could be damaged from the rapid temperature changes that occur through heating and cooling.

Average Cost of COB Supply

  • Sand:
    • 60 lbs-$4.75
    • Straw:
      • 1 Bale-$5.99
    • 4×4’s:
      • $5.50-$15.20

Depending on yardage

  • 2×4’s:
    • $6.99
    • Red brick:
      • 1-.69 cents
    • Baking brick:
      • 1- $1.20
    • Clay:
      • Free!

The costs above are estimates and based on local suppliers. Many recyclable materials can be used to make cob and thus, the cost may be lower. The possibilities are ENDLESS when it comes to cob!


Diagram of Our Cob Oven’s Design

Consistency of Cob

Construction Photos!


Construction on the cob oven took place this past Saturday. Stay tuned for pictures and details on how it was made!

Inexpensive Cob Oven…

Here’s a great article on how to build an inexpensive cob oven. A place to bake fresh breads, pizzas, and anything else you can imagine for under $20…such a great deal!


First Post!

The Newsletter group will be sending out their final product (a newsletter, naturally) at the end of the project so there will not be many updates from them until that point. The History group has already begun their research on the previous technologies and materials used in production and how we have grown closer and closer to sustainable development.
Here’s what they’ve found:
Starting with the Native Americans, buildings/structures were built from hides. Even though all of the animal was used, there were still a limited number of animals and that made the process was unsustainable. Settlers used wood to build log cabins. The use of logs combined with the population growth led to a shortage of available forest resources. It wasn’t until the 1960s in which we saw the idea of sustainable development really come to light. This revolution led us to where we are now, a time in which natural building is becoming more and more necessary, for both our environment and our future.
In the coming weeks we will get to hear more about natural building and the pros and cons of cob building from the History group.
We will also hear the preliminary findings from the Design and Costs team!