The foundations are usually un-mortared river boulders, no damp course, then walls of either unbaked mud bricks or mud and straw. Walls can be up to a metre thick, and plastered with mud and lime. The paint finish is unslaked lime mixed in drums with fat or oil; this get really hot as it "works", and is applied inside and out with the outer coat being repeated annually or every few years as necessary. Once you start painting with a lime wash you can never migrate to a modern paint as it will never stick to the porous, flaky lime. The lime, for better or worse!, allows the walls to breathe. Lintels and roof timbers are of local hardwood, poplar or gum, and the roofs of local thatch. Interior floors were usually either packed and polished cow dung, Batavian red cobble blocks, clay or even peach stones. In residential situations more affluent owners would fit suspended yellow wood floors. The result is durable and well insulated, but requires constant maintenance. The architectural design and execution of these buildings was developed by Dutch settlers from the late 1600's onwards and is referred to as "Cape Dutch".