Mudbrick repairs use original recipe at Hayes Engineering

Heritage stonemason Ross Miller is bringing his years of expertise to the repair of the Single Men’s Quarters at Hayes Engineering.

Stonemason Ross Miller works on a mudbrick in the side of Hayes Engineering. Behind him is a blue tarpaulin.
Ross working on repairing mudbrick in the Single Men’s Quarters at Hayes Engineering. Photo: HNZPT.expand/collapse

In the tussocky plains of central Otago, early Pākehā settlers and farmers were faced with a conundrum – how would they build their homes and outbuildings without trees? The Hayes family, like many others before them, used the simple technology of homemade, sun-dried mud bricks.

Mud, tussock, and cow dung were mixed by a team of oxen, then packed into wooden, tin-lined moulds, which were then left in the hot Otago sun to bake. The bricks were then laid with mortar and given several layers of limewash to protect against the elements.

Circa 10 years ago, when Heritage New Zealand Pouhere Taonga restored the Hayes Homestead, the restorers knew there must be a recipe for the mudbrick and limewash – the Hayes were meticulous at keeping records. Eventually, they found the recipe in a family cookbook.

All this information comes in useful for Ross, as he takes on repairs at the Single Men’s Quarters, built in 1914. He has discovered that under the limewash some of the organic material is deteriorating.

“The challenge is to remove the damaged brick, stabilise the gap to hold up the wall, and then insert a new brick,” says Ross. Fortunately, spare historic mudbricks from another dismantled farm building are available for repairs.

Ross has tested different combinations for the limewash, until he came up with the best ratios of lime and mud. The work on the Single Men’s Quarters needs to be finished before the first autumn frosts make it too damp to work on the mudbricks.

Jess Armstrong, Acting Manager of Heritage Assets who is based at Hayes, has found the repair process fascinating:

“I have learnt so much from Ross over the years. I find it fascinating, especially as the old homestead on my husband’s family farm is made from mudbrick,” she says.

Jess has put her learning about mudbrick technology to work assessing all the different parts of Hayes Engineering buildings.

“The south-facing walls, which bear the brunt of the rain and southerly winds need regular limewashing, whereas the north-facing walls only need to be done every 10 years or so,” she says.

Hayes has several mudbrick buildings dating from 1895-1930s, and it is Jess’ goal to implement a comprehensive and regular lime-washing roster.

"This is a complex site, and it needs to be closely monitored and cared for," she says.

- Rosemary Baird