Cob Oven Construction at the Willow Green Community Garden

As we contacted community groups to see if they were interested in pursuing a project with us, we discovered an evident interest in natural building for both the purposes of sustainability and community development. However, the majority of community groups weren’t prepared to invest in this type of project for different reasons. We were even more thankful then that the Cherry Park Neighbourhood Association (CPNA) was prepared for it. In their survey of the Cherry Park neighbourhood, they identified newcomer populations who had used cob ovens in their countries of origin, and they had the space needed for it.

The Willow Green community garden on Cherry Street attracted city dwellers beyond the borders of the neighbourhood. An extension of it was therefore formed with larger plots for long-time gardeners. This site contained space for the project. It lies about 1,000 feet north of the “Old Willow Green Garden”. You can find it by following the path along the creek. A mulberry tree grows near it.

Once the CPNA established that there was community interest and space, we were invited to present the project at the Cherry Festival last year. With a model of a cob oven with us, we engaged with young and old to explain the stages of the project. We received support from everyone we met.

Later we collaborated with the CPNA to write a proposal to the City of Kitchener. We applied for a Neighbourhood Matching Fund Grant, which was newly developed for grassroots initiatives. It was exciting when the proposal was approved and we were offered the grant. At this time, the Highland-Stirling Community Group had invited us to help build a cob oven at the Mill Courtland Community Centre.

With two projects underway, we coordinated our time with both community groups in order to help them as much as we could. Although there were days when we needed to divide our time, they proved to be useful. We were able to transfer the lessons we learned while building at one site to the other.

This project was completed in stages. These steps will sound familiar to anyone who read our former post!

The first stage involved digging the ground, pouring concrete in it to create a platform, and constructing a wooden shelter on it. A shelter is important for the sustainability of a cob oven. Exposure to water can cause damage over time.


The CPNA decided to form a slanted roof in order to collect rain water.


The second stage involved forming a base for the cob oven. This unfolded in a sequence of steps:

1. We stacked bricks in an interlocking pattern and then leveled them.


2. We filled the base with a sand and gravel mixture and we packed it with wooden sticks to reduce the air in it.

3. We positioned a layer of empty glass bottles near the top and then covered them with sand. The bottles will serve to insulate the oven by blocking any moisture that surfaces from the ground.

4. We laid down fire brick and then leveled it. This will be the bottom of the oven.


The third stage involved building the cob oven. This also occurred in a sequence of steps:

1. We created a dome out of sand on top of the fire brick.


2. We covered this dome with newspaper strips that were dipped in water.


3. We covered this layer with cob, a mixture of sand, clay, and water. It was fun to use our feet to mix it!


4. We added straw to this mixture. This is another form of cob.


5. A piece of Styrofoam in the shape of an oven door was then placed along the edge of the dome and cob was packed around it. A wooden version will be made later.


The CPNA kindly added a sign in recognition of all the groups involved in the project.


6. The sand at the core of the dome was removed.


7. We lit a fire with newspaper to begin drying out the layers of cob from inside the oven.


If you’d like to try it out, please send an email to the CPNA at Once you’re on their Baker’s List, you’ll be notified whenever the cob oven will be heated and open for you to use.

Thank you to the CPNA for their commitment to this project, the City of Kitchener for their support, and all the volunteers who offered us their time and effort.


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