This is an effective technique for maintaining proper ventilation though depending on the type of building maintaining proper storage temperature and RH may be difficult. Granaries or other storage buildings typically consist of a round hut with walls made of straw, mud, clay and wood and a conical straw roof. These are commonly supported above ground by a system of legs to keep the crop dry and away from animals, rodents and pests. Typically sweet potatoes are stored and eaten fresh. However, there are some simple methods used to increase their storability that can be used in conjunction with other storage methods. Drying and curing of sweet potatoes are two common methods to prepare them prior to storage. Drying of tubers is done on those that are too damaged to be stored fresh but still have edible material on them. This involves slicing tubers to a thickness of approximately 2–4 mm and then laying them out in the sun for four days or until they are rid of most of their moisture. During drying the potatoes can be covered in prickly bushes or thorns to ward off animals. Dried slices can be kept in-doors or in raised silos until eaten. Drying removes moisture, reduces bacterial growth, and inactivates metabolic processes and enzymatic decomposition. Curing is a technique done to toughen up the outer layer of skin (periderm). It is a measure that prevents against excessive moisture loss, entry of microorganisms into the plant and even facilitates healing of mechanically damaged tubers. Curing is done by exposing the whole potatoes to a moderately high temperature for several days immediately following harvest.; and 80–95% RH for 4–10 days has been found to be adequate curing conditions A common method to cure without use of incubation equipment is to wrap tubers in black polythene sheets and leave out in the sun for 5 days. The black sheet keeps moisture in and collects heat to reach necessary conditions for curing. Immediately following curing the temperature must be dropped quickly in order to avoid sprouting damage.