witchert is a corruption of 'white earth' which roughly describes the lime rich sub soil that lies above the Portland Limestone belt that passes through the Vale of Aylesbury.
Walls were built by piling the sub soil in heaps and were then thoroughly soaked, mixed with chopped straw (to make the glutinous mix workable) and laid in 'raises' or 'berries' each about 18 inches or half a metre high. The walls have a base plinth of rubblestone, this is called the grumpling. On top of the grumpling the wychert is built up in layers called berries, these must be left to dry before adding the next berry. The walls are then topped with tiles for weather protection.
Being a natural building material Wychert requires natural products to compliment it. The use of cement and Gypsum based product are avoided as much as possible, along with modern paints as they stop walls breathing trapping in moisture. Instead lime and lime based products are used, which work with the Wychert allowing it to breath.