If a family desires a sealed outer burial container to protect the casket, what is the best option to offer?

The best option for a family seeking a sealed outer burial container to protect the casket is a vault. A vault is designed specifically to provide a higher level of protection and can be sealed to prevent water and soil from entering. This feature not only helps in preserving the integrity of the casket but also provides additional support to prevent the ground from sinking over time.

While a grave liner and a concrete box may offer some degree of support and protection, they typically do not have the same sealing capabilities as a vault. Grave liners are meant to support the weight of the soil above but may not completely prevent moisture infiltration. Concrete boxes may provide basic protection but are generally not sealed units.

Therefore, the vault is considered the superior choice when it comes to ensuring both the physical protection of the casket and safeguarding against environmental elements.