Type A are usually traditional stone masonry buildings of two or three stories which have been the dominant building type in the area for many centuries; mostly consist of a coarse, short-bedded, ill-laid rubble masonry with great thickness of mortar joints and very thcik walls. Many have had additional stories added in new materials without strengthening the supporting structure. Fir timber made up the floor joists and roof rafters, but are often replaced by concrete floors supported by steel joists and ceramic planks that are not bonded together laterally nor tied into the walls.