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
- 60 lbs-$4.75
- 1 Bale-$5.99
Depending on yardage
- Red brick:
- 1-.69 cents
- Baking brick:
- 1- $1.20
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!