Thus, those kilns resemble western types, where fuel is continually added to the fire to bring the charge up to the necessary temperature. To prepare the kiln, a thick layer of fuel is laid over the bottom. Then, the dry pottery, interspersed with additional fuel, is piled on top until the charge has been built up to a rounded mass several feet higher than the kiln wall. The entire charge is then covered with large pieces of broken pottery that help retain some heat and protect the pottery from direct contact with cool air. The charge is lit from the bottom and all the fuel is consumed in from two to four hours.
Small kilns permit the firing of one to five pots at a time.
Larger kilns like those used by the Hausa in Northern Nigeria and the Mossi of Burkina Faso can fire one hundred pots or more in one charge.