The main purpose of a burial vault is to protect the integrity of the grave from the heavy equipment, such as a backhoe, that the grounds crew uses to prepare a grave. A lined vault is not technically water proof, however, with the tongue and groove lid of the lined vaults we use, that are supported by the weight of earth, we rarely see one get moisture inside if we have to exhume a body. Not useless at all and in fact most cemeteries require them now to keep the grave site from sinking in, which would be traumatic for a family.
Why don't you make a water proof vault if people are willing to pay for it?
It's useless because it's not water proof.
The main purpose of a burial vault is to protect the integrity of the grave from the heavy equipment, such as a backhoe, that the grounds crew uses to prepare a grave. A lined vault is not technically water proof, however, with the tongue and groove lid of the lined vaults we use, that are supported by the weight of earth, we rarely see one get moisture inside if we have to exhume a body. Not useless at all and in fact most cemeteries require them now to keep the grave site from sinking in, which would be traumatic for a family.