ferrocement

thumb|Mulberry harbour remains at [[Arromanches]] thumb|Lambot's original 1848 bateau in the Brignoles Museum in France. thumb|Ferrocement hull under construction thumb|A particularly fair ferrocement vessel, the staysail schooner "Rich Harvest"

Ferrocement or ferro-cement is a system of construction using reinforced mortar or plaster (lime or cement, sand, and water) applied over an "armature" of metal mesh, woven, expanded metal, or metal-fibers, and closely spaced thin steel rods such as rebar. The metal commonly used is iron or some type of steel, and the mesh is made with wire with a diameter between 0.5 mm and 1 mm. The cement is typically a very rich mix of sand and cement in a 3:1 ratio; when used for making boards, no gravel is used, so that the material is not concrete.