Alan Cash                                                                                                   July 5, 2014

BUILDING A 24” COB OVEN AT MY HOME

Overview of project:

Placement:

My vision is to design and build a 24” cob oven behind my current deck. 

This has been a long-term goal.

The cob oven will be constructed approx 8-10ft from the chimney and house. 

I will have to level the ground, move my fence and modify the deck to accommodate the structure.

I have surveyed all round my property and this seems the most convenient place for the oven. There will be easy access to kitchen for prep work and a larger deck area around the oven for social space.

The area behind the current fence will have to be leveled and made solid by laying down decomposed granite. This is where the foundation of the oven will be built.

Considerations and safety concerns:

• The structure may be too close to the house

• Large redwood tree very close that will have to be pruned.

• Smoke and sparks are a concern as this area is relatively close to neighboring properties.

• Area attracts a lot of moisture during the winter and also the summer fog drip. Provisions for a simple roof over the oven need consideration.

All safety concerns will be addressed before I proceed.

Location 

Picture showing inside current area of deck and
fence edge that will be moved further back

Picture showing other side of deck and the
intended area for cob oven construction

Different view showing the chimney

Test for site soil

I will do all soil tests using a combination of site soil, aggregate, straw and sand to determine the best ratios for sturdy material of thermal layer, insulating layer and plaster.

Materials

I already have some Napa Basalt stone for the foundation left from stone work from previous landscape job.

Other materials needed:

•Firebricks

•Flue

•Damper

•Spark arrester

•Slate or flagstone (American Soil and Stone)

•Napa Basalt (American Soil and Stone)

• Decomposed granite

• Sand

• Buckets and some tools

I will work out a budget for materials, but priority will be to scavenge and find as much as possible.

  

Design

I envision a simple structure comprising of one or two arches and one oven door. The flue will have a built in smoke damper and spark arrester.

The design will be drawn to scale using Sketch Up and show each component in detail. Oven door will be either metal or wood to be decided.

Roof and enclosure will be part of design consideration, perhaps at a later date.

I will draw detailed diagrams showing all components of the oven.

Ultimately. the oven must be beautiful and have the aesthetics that I’m looking for.

This project will be used as a guide and will not be built this semester.