Burial vaults typically refer to reinforced containers that the deceased are buried inside. The vault is separate from the casket; the casket goes inside the vault. Burial vaults are used to prevent the soil over a grave from sinking and to prevent pressure from the earth and large cemetery equipment from breaking the casket. In rare cases, a tomb burial vault is used in place of a traditional burial vault.
A grave liner is the simplest kind of burial vault. It is designed to support the soil only, not necessarily protect the casket. It is a five-face rectangular box (there is no bottom) typically made of concrete or another porous material that will allow water to soak through. The casket will not break because of earth pressures or heavy equipment above, but water damage to the casket is likely over time. Grave liners are the least expensive option for those burying a loved one. Grave liners and other burial vaults are not required by law, though some cemeteries require a structure to keep soil from sinking. Grave liners will not prevent the decomposition of a buried body.
A grave vault is different from a liner in that it completely surrounds the casket, providing maximum protection from the earth surrounding it. Vaults can be made of concrete and lined with plastic or metal. They can be double- or triple-lined to provide even more support. Funeral homes are required to disclose a list of prices for burial vaults before they present any of their grave vaults to a family. They cannot charge a fee or penalise a family for purchasing a grave vault from a third party. Vaults are more expensive than liners, though some families prefer them because grave vaults can be personalised with writing or symbols. They may also give loved ones peace of mind knowing the deceased is as protected as possible. Grave vaults do not prevent the decay of a body over time.
A tomb is a large room, usually underground or in an elaborate structure, where a deceased person's casket is placed. Tombs were more common in the past for notable people like rulers, but in modern times a tomb may be created to house deceased members of an entire family. Other instances include religious leaders, like priests or monks, being buried in a tomb beneath their church along with past leaders. Tombs are expensive to construct and obtain, so most families with "family tomb" tend to be wealthy. The tomb acts as a very large burial vault, protecting the casket and providing support beneath the earth or beneath a building. Tombs will not prevent the decomposition of a body over time.