In Genesis, pitch covered Noah’s Ark inside and outside to make it watertight.
Genesis 6:14 tells Noah to cover the Ark “within and without” with pitch. Pitch is a sticky waterproofing material historically made from natural bitumen, tar, or resinous substances, depending on the culture and period. The biblical instruction therefore describes sealing the vessel’s wooden structure against water.
The Hebrew word translated as “pitch” is related to a verb meaning to cover or coat, and some translations emphasize the waterproofing function. This detail is separate from the Ark’s construction material: Genesis names gopher wood for the structure and pitch for sealing it. Later retellings sometimes mention tar or bitumen instead, but these are translation choices for the same general waterproofing substance.