In Genesis, pitch waterproofed Noah’s Ark inside and outside. Genesis 6:14 tells Noah to coat the Ark with pitch, a sticky sealing substance intended to keep water from entering through gaps in the construction.
The Hebrew wording is related to terms for covering or sealing, and many translations use “pitch.” The text does not specify whether the material was mineral bitumen, a plant-derived resin, or another ancient waterproofing compound. Ancient boatbuilders in the Near East did use bitumen and related substances to seal wooden or reed vessels.
This instruction is separate from the Ark’s building material. Genesis names gopher wood for construction and pitch for waterproofing, so the two terms should not be treated as synonyms. The Ark was also described as having compartments and an opening, features that belong to its internal arrangement and ventilation rather than its waterproof coating.
Later retellings sometimes focus on the Ark’s enormous size while omitting this practical detail. The pitch instruction is one of the narrative’s clearest construction specifications.