Clinker built (also known as lapstrake) is a method of boat building where the edges of hull planks overlap each other. Where necessary in larger craft, shorter planks can be joined end to end, creating a longer strake or hull plank. The technique originated in Scandinavia, and was successfully used by the Anglo-Saxons, Frisians, Scandinavians, typically in the vessels known as cogs employed by the Hanseatic League. Carvel construction, where plank edges are butted smoothly, seam to seam, supplanted clinker construction in large vessels as the demand for capacity surpassed the limits of clinker construction. (See Comparison between clinker and carvel below.).

Examples of clinker-built boats that are directly descended from those of the early medieval period are seen in the traditional round-bottomed Thames skiffs, and the larger (originally) cargo-carrying Norfolk wherries of England.