In Genesis, Noah used pitch to waterproof the Ark inside and outside.
Genesis 6:14 tells Noah to make the ark from gopher wood and cover it with pitch on the inside and outside. The instruction appears before the measurements and animal-preservation details, making waterproofing one of the earliest construction requirements in the account.
Pitch is a general term for a thick, water-resistant substance historically obtained from natural sources such as bitumen, resin, or tar-like materials. The biblical text does not specify its chemical composition, how it was produced, or how much was required. It simply identifies the coating used on both surfaces.
This detail is sometimes confused with the ark’s building material. Gopher wood refers to what the vessel was made from, while pitch refers to its protective coating. Genesis also mentions rooms or compartments and a roof, but it does not give a complete description of the ark’s tools, joints, or construction labor.