Do It Yourself Underground Vaults

Excavate a suitably sized trench that will allow for the placement of your sea container. This is best done with a heavy excavator, which can remove large amounts of earth quickly. Sea containers are generally 8 feet tall, so your trench should be at least 9 feet deep, or more depending on your needs.

Haul the sea container into the trench with the backhoe. Permanently sealing the doors on the end of the container would be advisable to prevent moisture from entering through them.

Cut out an entrance to the container through the top of it by cutting a 40-inch diameter hole through the roof with your grinder.

Place your length of concrete tubing over the hole in the top of the container, and secure it in place to the surface of the container with concrete.

Back fill the trench and container with some of the earth that was excavated. The top of the concrete entrance tube should be level with the surrounding surface of the ground. Excess excavated earth will need to be removed or redistributed.

Choose and mount a suitably secure door to fasten over the opening of the concrete tube. There are a variety of different door and lock mechanisms that can be custom made for your concrete tube that provide varying levels of security. Hiding the entrance with foliage may provide increased security.