Stone walls are a kind of masonry construction which have been made for thousands of years. First they were constructed by farmers and primitive people by piling loose field stones in what is called a dry stone wall, then later with the use of mortar and plaster especially in the construction of city walls, castles, and other fortifications prior to and during the Middle Ages.
They are usually made of local stone, varying from limestone and flint to granite and sandstone. However, the quality of building stone varies greatly, both in terms of its endurance to weathering, resistance to water penetration and ability to be worked into regular shapes before construction. Worked stone is usually known as ashlar, and they are often used for corners in stone buildings. Granite is thus very resistant to weathering, while some limestones are very weak. Some limestones, however, such as Portland stone have a deserved reputation for resistance to the weather.
Large structures are usually made of very thick walls, so that castles and cathedrals possess walls which may be up to 12 feet thick. They normally consist of a layered stone exterior and rubble infill.
See also