Sourcing Materials

Structural

Having looked at various methods of construction (including timber and paper, as shown below), we decided that using aluminium conduits would be the most structurally sound option, as well as the most durable. The lightweight properties of aluminium will allow the dome to be constructed and transported with ease.

 

Julian’s Dad, a construction manager, suggested we try Capral – a cheaper option than Bunning’s, as well an independent Australian supplier. They were nice enough to cut the conduits down to the sizes we needed (specified below).

Cladding

We considered a few different cladding options.

One possibility was to cut triangular segments out of MDF, join them, then seal the joints with silicon.

Another possibility was to cover the structure in chicken wire, then cover it with papier mâché. We then would have needed to add a sealant and an internal insulative layer.

We also considered glad wrap – this would look fantastic, however it would not be an appropriate response to an ESD brief. Glad wrap itself is not a sustainable product, nor would it provide any insulation.

We kept coming back to the idea of using mud and straw, and have settled on this as our final choice.  We will attach chicken wire to the aluminium structure using cable ties. This will provide something for the mud to stick onto.  The following video helped us figure out how to make the mud/straw mixture:

To make the mixture, we will need 2 parts clay-rich soil to 1 part sand. We will estimate the amount of water and straw we need. All components can be sourced from parts of Julian’s farm. We have found a particularly rich deposit of clay, so will most likely use less than the 2:1 ratio suggests.