Generally, each prefabricated underground storm shelter manufacturer has a set of instructions on how to install its unit, so always follow those instructions for best results. The process usually involves digging a hole, inserting pipes, marking out the placement of the building, pouring concrete and erecting the shelter.
Experts recommend hiring a professional, experienced contractor to install an underground storm shelter. However, those with experience may be able to complete the task using the steps below.
- Plan and lay out the area
- Dig a hole
- Insert the pipes
- Mark out the auger placement
- Place concrete over the pipes
- Back fill the area
Plan and lay out the area for the shelter. Make sure the door sits at least six inches above ground level.
Dig a hole for the refuge that is 5 1/2 to seven feet deep for refuge. Dig a hole for the shelter that is 12 feet long and 10 feet wide.
Insert the pipes into the holes, placing them in prefabricated sleeves when applicable.
Place the augers close to each side of the shelter in the back and front. Screw the augers into the ground.
Pour concrete over the pipes, keeping the shelter level. If using concrete blocks, make sure they have a combined weight of 5,000 pounds.
Replace the dirt around the shelter, making sure to pack it under the steps. Check to make sure there are no air voids. Check it after a few days or after a rainstorm and fill in again where needed.