According to Genesis, Noah’s Ark was sealed with pitch. Genesis 6:14 tells Noah to make the Ark from gopher wood and cover it with pitch inside and outside.
Pitch is a general term for a thick, waterproofing substance derived from tar, bitumen, or similar materials. In the ancient Near East, bitumen was widely used to seal boats, baskets, buildings, and other objects against water. The biblical instruction therefore describes a practical waterproofing process as well as a symbolic act of preservation.
The Hebrew wording is related to the verb meaning “to cover” or “to smear,” and translations commonly use “pitch.” The passage does not identify a modern chemical formula or specify which natural source supplied the substance.
Readers sometimes confuse pitch with the wood itself. In Genesis, gopher wood is the construction material, while pitch is the coating applied to the Ark’s interior and exterior. The text does not identify what “gopher wood” means in modern botanical terms.