Genesis says Noah used pitch to seal Noah’s Ark.
Genesis 6:14 instructs Noah to cover the Ark with pitch inside and outside. The material is presented as a waterproofing substance applied to the vessel’s surfaces, helping explain how the enormous enclosed craft was intended to withstand the floodwaters in the story.
English translations vary slightly in wording, using terms such as pitch, bitumen, or tar. These renderings reflect translation choices around an ancient waterproofing material rather than different substances explicitly listed by Genesis. “Pitch” is the traditional concise answer in English.
The passage mentions pitch separately from gopher wood, the material used to construct the Ark. It also says the Ark had rooms, three levels, and a side door. Later artistic depictions may show elaborate construction techniques, but Genesis itself gives only this brief waterproofing instruction and does not describe a detailed shipbuilding process.