A general term referring to any container which is designed for placement in the grave around the casket, including, but not limited to, containers commonly known as burial vaults, grave boxes, and grave liners.
Outer Burial Container
To support the weight of the earth over the grave. Any burial not accompanied by such a container is subject to eventual collaspe due to the weight of the earth crushing down on the unprotected casket.
Primary Purpose of the Outer Burial Container
While these do not require the use of an outer burial container, most cemeteries, in the interest of minimizing maintenance and liability issues, will require either a burial vault or grave liner be used in conjunction with any interment.
State and Federal Law
Forces that the outer burial container is subject to.
Loads
Four Load Types
Comprised of the weight of the soil above the outer burial container, as well as the force exerted by the earth against the outer burial container’s sides and bottom. Also encompasses the forces resulting from cyclic freezing and thawing of the earth.
Static Load
Typically of short duration, can be quite heavy, as in the case when soil from a grave under excavation is placed on top of an existing grave.
Differential Loads
One that varies in its intensity and is usually temporal in nature, such as the weight of a dump truck that might drive over the grave, or the force exerted by a backhoe parked above an existing grave while it excavates another grave nearby.
Dynamic Load
Encountered by the outer burial container when a sudden and powerful application of force is introduced to the gravesite, as occurs when a large amount of fill-dirt is dumped onto the outer burial container as the grave is filled, when a mechanical tamper is utilized in filling the grave, or when a backhoe’s bucket is forcefully dropped on a grave.
Impact Load
An outer enclosure which offers protection from the earth load as well as possessing sealing qualities.
Burial Vault
An outer enclosure which offers protection from the earth load without protection from the elements.
Grave Liner
May vary substantially. The standard is 30 inches wide by 86 inches long.
Outside Dimensions of Outer Burial Containers
A two-piece affair consisting of a bse and cap (or “cover”). May or may not be internally reinforced with smooth steel bar or rebar, and the interior i typically lined with a material designed to further strengthen the structure and to resist the entrance of water.
Concrete Burial Vaults
Materials Used to Line Concrete Vaults
A very tough and resistant plastic.
ABS (Acrylonitrile Butadiene Styrene)
Placed within the base and cap of the concrete vault. When used, the metal linings are usually present in addition to this initial lining material.
Separate Synthetic Liners
Used by some vault manufacturers a both a lining and an exterior coating. Does little to strengthen the vault structure itself, but does reduce the concrete’s permeability.
Asphalt
As a result, specialized and expensive equipment is necessary to transport the vault from its place of manufacture to the cemetery and install it within the grave.
Concrete Burial Vaults Weigh in Well Over 2,000lbs (1 ton)
Used by nearly every concrete burial vault. A method of closure that utilizes an epoxy compound in conjunction with tongue-in-groove construction at the top edge and the lid of the vault.
Top Seal Method of Closure
Concrete Vault Exterior Finishing Treatments
Metal Burial Vaults
Steel that has been coated with zinc for increased resistance to rust.
Galvanized
A method of closure that utilizes the air pressure created by placing the dome (A) of the vault onto the base (B) of the vault.
Air Seal (Diving Bell)
Gives the unit exceptional load resistance, and its curved interior allows collected condensation to roll down the sides of the vault and back into the earth.
The Arched Dome of the Metal Burial Vault