Caulking is a term used to describe several different process to seal joints or seams in various structures and certain types of piping. The oldest form of caulking is used to make the seams in wooden boats or ships watertight, by driving fiberous materials into the wedge-shaped seams between planks. A related process was formerly employed to join sections of cast iron sewerage pipe.
Caulking is also the term to describe the process used to make riveted iron or steel ships and boilers watertight or steamtight.
The same term also refers to the application of flexible sealing compounds to close up gaps in buildings and other structures against water, air, dust, insects, or as a component in firestopping.