In Genesis, Noah used pitch to cover the Ark’s interior and exterior.
Genesis 6:14 instructs Noah to make the ark from gopher wood and cover it inside and outside with pitch. Pitch is a waterproofing substance made from tar-like bitumen or resinous material, so the instruction has a practical function: sealing the vessel against water.
The Hebrew term translated as pitch is related to the idea of covering or atonement, and translations differ slightly in how they render the material. English Bibles commonly use “pitch,” while some versions explain it as bitumen or waterproofing material.
Pitch is not the same as the ark’s wood. The wood forms the structure; the pitch forms the protective coating. It is also distinct from the ark’s dimensions and from the window and door mentioned elsewhere in the construction instructions.