What is a "grave liner" or "vault"?

What is a "grave liner" or "vault"?

A grave liner or a vault is an outer protective container for the casket itself. It also helps stop the ground from sinking when the casket starts to deteriorate. You do need to purchase a grave liner or a vault if the cemetery requires that you do so. There is no law that requires grave liners or vaults, but cemeteries set up rules and regulations for their benefit to prevent things like sinking graves. The outer burial container or the vault helps in stopping that process. You don't want to see that there's a divot in the ground of a cemetery. It may cause the family to think that somebody has actually been removed and that may not be the case. After a normal period of time, decomposition does take place of all the parts that are in the ground, but a grave liner or a vault can conceal this.