How to Build a Hillside Storm Shelter

More than half of the United States lie in a broad strip between the Appalachian and Rocky Mountains that is commonly called Tornado Alley. It has more tornado activity than any other area of the world. The rest of the country is not immune; tornadoes have occurred in every state. To help protect yourself from storms and tornado, I show you how to make a storm-shelter of your own.

Instructions

Difficulty: Moderate

Things You’ll Need:

• steel panels or reinforced concrete
• corrugated steel culverts, steel plate (galvanized or epoxy coated)
• reinforced fiberglass, high-density polyethylene
• concrete reinforced with rebar (steel rods) or fibermesh
• wood, aluminum, steel
• Stainless steel and zinc

1. Introduction step: Prefabricated underground shelters are made from various materials, including corrugated steel culverts, steel plate (perhaps galvanized or epoxy coated), reinforced fiberglass, high-density polyethylene, and concrete reinforced with rebar (steel rods) or fibermesh.
2. Use Steel molds to cast the upper and lower sections of the shelter. Walls are 3-4 in (7.5-10 cm) thick, while floors and ceilings are 5-6 in (13-15 cm) thick.
3. Metal reinforcement is placed in each mold. For example, one manufacturer uses 0.5-in (1.3 cm) diameter steel rebar placed at 12-in (30-cm) spacing.
4. Concrete is poured into the mold. The mold is vibrated to minimize air bubbles.
5. When the concrete has set, the shell is removed from the mold and inspected for flaws.
6. The top and bottom halves of the shell are joined. Their edges are designed to interlock, and a tar sealant or waterproof mastic is applied prior to mating the two pieces. Steel straps are placed across the seams and bolted in place to reinforce the joint.
7. Steps or a ladder are installed. The door is mounted using multiple hinges, a piano hinge, or a frame that allows the door to slide open and closed. One or two air vents are installed. Each consists of a vertical pipe topped with either a wind turbine or a screen-covered 180° elbow.
8. Shelter doors or hatches are made from steel, fiberglass, or steel-plated plywood or aluminum.
9. Installtion:
   A backhoe is used to dig a hole for the shelter. A worker with a shovel hand-finishes the hole, leveling the bottom and clearing the corners. The hole should be about 2 ft (61 cm) larger than the shelter in each dimension
10. Installtion:
    The backhoe or a crane-equipped tow truck is used to lift the shelter and lower it into the hole. Some shelters are equipped with fittings that the lifting device can grasp. Others are lifted by chains attached to brackets on the outside of the shelter or by a pair of nylon straps wrapped vertically around the shelter
11. Installtion:
    Because they could float if the ground became saturated, steel and fiberglass shelters must be anchored during installation. This is usually done by bolting or chaining them to mounts embedded in a concrete foundation. Some manufacturers also recommend pouring concrete around the shelter's walls.
12. Installtion:
    If concrete is not poured around the shelter, soil excavated from the installation site is generally used to backfill the remaining void around the shelter. If the shelter is also intended to function as a bomb shelter, backfilling consists of gravel or crushed rock.
13. Installtion:
    Some underground shelters are installed with their tops at ground level, but most are designed to be covered with 2-3 ft (61-91 cm) of soil. The surface may then be planted with grass or topped with patio decking.

Tips & Warnings

• Storm shelters are usually made out of concrete or steel, but recent technological developments have shown that fiberglass is becoming very popular.
• Also Fiberglass is mildew resistant and usually guaranteed not to rust or corrode