Lime Plaster and Lime-wash

After two weeks of not coming to Bonnievale as a result of organising restoration work to be carried out on the Cape Town cottages, it was good to be home again. Autumn came for an extended stay with the neatly mowed lawn scattered with oak leaves and the crinium moorei flowers having gone to seed.

Lime-washed wall drying

With work on the Cape Town cottages starting in April, we decided to use our leave to do some restoration work on the homestead at Towerwater. A wall had incurred some rainwater damage a while back and with clay brick building it is best to repair any exposed adobe as soon as possible.

Lime-wash freshly applied

After we cleared the voorkamer Keith mixed the adobe friendly plaster comprising of sand, building lime and cement in quantities to a ratio of 8:2:1. Although lime cures more slowly than cement, it does hold many advantages as a workable, self-healing, breathable, nearly carbon neutral material, making it much more suited to natural building practise. As the house is built with sun-baked clay bricks, it is very important that the plaster should be compatible with the original clay bricks and adobe plaster finishing of the building.

Chandelier reflecting against freshly lime-washed walls

The 8:2:1 mix is used by most restoration architects and practitioners working with old Cape Dutch buildings. We have found that it works well with the old plaster.  Traditional buildings need to ‘breathe’ so as to allow moisture in the walls to evaporate through the external plaster/render and paint finishes. Many problems on old buildings are caused by using the wrong mixture, usually cement rich, trapping moisture in the walls thereby causing bigger problems.

Drying lime-wash brush strokes

 Prior to fixing the cracks and spots of exposed adobe, the walls were dampened and again the next day, before Shawn lime-washed the room. Lime-wash is a mixture of slaked lime (calcium hydroxide) in water which sets slowly by absorbing carbon dioxide from the air. We do not mix our own lime-wash but use a ready mixed product, Glutone. The finish we get on the walls is softer, warmer and awash with reflective salt crystals.

For two days the dining-room table looked like we were planning a major drinks party with all the glasses and liquor packed out on it when Keith emptied the jonkmanskas that had to be removed from the voorkamer.

Lime-washed walls and handmade terracotta floor tiles

But the disruption was worth seeing the voorkamer in pristine condition again. Looking fresh with its two layers of peach coloured lime wash, reminiscent of the first colour to be found on the wall.