Fireproof

Fireproof vaults

Fireproof vaults to protect important paper documents are usually built using concrete or masonry blocks as the primary building material. In the event of a fire, the chemically-bound water within the concrete or masonry blocks is forced into the vault chamber as steam, which soaks the paper documents to keep them from igniting. This steam also helps keep the temperature inside the vault chamber below the critical 176.7 °C (350 °F) threshold, which is the point at which information on paper documents is destroyed. The paper can later be remediated with a freeze drying process if the fire is extinguished before internal temperatures exceed 176.7 °C (350 °F). An alternate less expensive and time-consuming construction method is using dry insulating material.