Genesis tells Noah to seal Noah’s Ark with pitch. In Genesis 6:14, Noah is instructed to make the Ark from gopher wood and cover it with pitch inside and outside.
Pitch is a tar-like waterproofing substance used to protect wood and reduce leakage. The Hebrew term translated as pitch is related to a word for covering or coating, and translations can differ slightly in how they render the construction instruction.
The passage presents waterproofing as part of the Ark’s preparation before the Flood. It does not identify a modern chemical formula or specify exactly how the pitch was produced.
A common confusion is to treat gopher wood as the sealing material. In the text, gopher wood is the building material, while pitch is the coating applied to the Ark’s inner and outer surfaces.