According to Genesis, pitch seals Noah’s Ark.
Genesis 6:14 instructs Noah to cover the ark inside and outside with pitch. The substance is presented as a waterproofing material, helping make the enormous vessel watertight during the Flood. The Hebrew term is commonly translated as pitch, although translations and commentators discuss its exact ancient composition.
Pitch generally refers to a sticky, waterproofing substance derived from petroleum, wood, or other organic materials. Ancient boatbuilders in several regions used bitumen-like materials to seal hulls and prevent water from entering seams. Genesis does not provide a recipe or identify a particular geological source.
This detail is separate from the type of wood mentioned in the same instruction. The wood forms the ark’s structure, while pitch provides sealing. Confusing those two materials produces an incorrect answer even though both appear in the same verse.