Roof Cob Oven

Sand about 30 40 gallons to fill oven s base and to put in cob as needed sand can often be found by bodies of water or collected from construction sites like subsoil.

Roof cob oven.

About 2 parts sand to 1 part clay. However i wouldn t recommend either of them for an oven. They way the roof is designed is to act in compression while exerting force on the bond beam which will act in tension. This cob oven was built leading up to the 2008 forest festival held in jackeys marsh tasmania.

Materials are raw and often sourced locally from the land. You would place a bond beam at the top of the cob wall ideally concrete and rebar or alternatively airplane cable connecting all the members of the roof in one big circle. Use your hands to carve out a small depression in the middle of the sand pile. Load up your wheelbarrow of sand and dump it in the middle of the tarp.

The oven is a design from build your own earth oven by kuko denzer. The smallest cob oven interior size that we ve heard of is 16 floor diameter. I m not in the construction trades. For the uninitiated cob is a combination of clay sand straw and water.

The oven i will propose and outline below is a highly insulated cob oven. Building the base for your cob oven the base of the oven would be constructed of 8 wide concrete blocks 8 x 8 x 16 so the concrete base needed to be 16 wide to provide a solid footing. Lay out a recycled lumber tarp at least 6 x8. Cob ovens are a relatively inexpensive way to bake with all the benefits of wood fire such as a hot hearth.

Pour off the water from 3 buckets of clay and dump the clay into the sand pile. Linseed oil and lime plaster are both sometimes used to seal cob against weather. Straw one bale to make cob make sure you do not confuse straw with hay. Lime wash creates a somewhat weather resistant surface but doesn t fully replace a roof.

When dry cob is extremely hard and durable and highly capable of storing heat given enough insulation the focus here is of course building with natural and recycled materials whenever possible. The inner most layer of mud or cob that we re going to put on our oven is just sand and clay. Any smaller and you won t have good heating or a large enough cooking surface. Dampness isn t a problem but exposure to driving rain or even steady dripping will quickly erode cob.