Kōrero: Building materials

This lime kiln at Kakahu in South Canterbury was built of local rock in 1882. Limestone was quarried nearby and run along a tramline to the kiln, where it was put in layers between firewood and burned. Burnt lime made a rather inferior mortar. Limestone was extensively quarried in different parts of the country to make cement, which is used to make concrete. Cement is a mixture of two main materials – lime and marl (a calcareous clay). In mid- to late-1800s New Zealand cement was of low quality, and it was not until high-quality cement (Portland cement) was made in the 1880s that it could compete with imports.