Carbon Neutral Patio Materials:
Benches and oven: clay, sand, straw
Finish on benches and oven: 3 coats Boiled linseed oil. Top coat of product called WoodPal (linseed oil, tung oil, and bees wax, oxide UV stabilizer). Product info states that it is carbon neutral as it is crop based rather than petroleum based.
Finish on greenhouse wall: earth plaster and painted with lime paint pigmented with iron oxides.