What are you looking for in a tornado shelter?






  • The Granger ISS is rotationally molded from Polyethylene, one of the most durable materials on the planet. The body of the ISS features double wall construction, with a ½ inch wall on the inside and a ½ inch wall on the outside. The two walls of the unit are filled with a non VOC foam adding extra strength, rigidity and condensation control.
  • The design and shape of the ISS is one of its most unique features. The units has a reverse taper design which means it is wider at the bottom than it is at the top. This reverse taper allows for the unit to be installed directly in the ground without an additional anchoring system. No messy concrete or complicated installation is needed. In fact, it’s the easiest shelter on the market to install.
  • A typical installation of the Granger ISS usually takes 4 hours or less. Simply dig the hole, position the unit and backfill with the dirt pulled out of the ground. The ISS can be installed outside an existing home or in new construction and even be retrofitted into certain areas.
  • The door is the most important part of any underground shelter because that is what is between you and the tornado. A door should be tested for safety following the FEMA 320 or FEMA 361 guidelines that tests the durability of the door to withstand debris flying at wind speeds of 250 MPH. The door of the ISS is a unique design that includes a double wall polyethylene exterior panel, a double wall polyethylene interior panel and a sheet of polycarbonate bolted between for ultimate safety.
  • Any door designed to protect you against a tornado is going to be heavy. Though lighter weight than other materials the polyethylene door of the ISS is no exception. To ensure the easiest entry and exit possible each Granger ISS comes with two gas assisted shocks to help open the door.
  • The Granger ISS Door has a triple locking system to ensure the highest level of safety and closure.
  • Minimize the look of your storm shelter or customize the door to blend in with your home. The unique feature of a colored door and vent allow the Granger ISS to look the way you want it to. Choose green to blend in with grass and landscaping, gray granite to blend in with a concrete floor or brown granite to blend in with mulch. Many other colors available upon request including your favorite team colors!
  • Each Granger ISS has articulating handrails that can be used for safer and easier entry into the unit. When not in use the handrails fold neatly to the side and do not take up valuable interior room. They can easily be raised again and locked into place upon exiting the unit for added safety.
  • With only three steps down to the seating of the unit, entry into the Granger ISS takes only seconds. The vertical entry is easy for most people and does not impede on the interior space.
  • The Granger ISS exceeds FEMA requirements for 6 adults though several more can fit in an emergency. Molded in circular seating allows occupants to sit comfortably with seating taking up as little space in the interior of the unit as possible. Even taller occupants will be able to sit straight with plenty of headroom, or stretch their legs by standing in the entry area.
  • Each Granger ISS comes complete with LED lighting. Simply touch the light upon entry to see inside the unit when the door is closed. Each unit comes with one LED light though additional lighting can be added
  • The Granger ISS is warrantied through the lifetime of the original owner for cracking, leaking, rotting, rusting or any type of deterioration of the body of the unit. This warranty also covers any other material or manufacturers defects.
  • If a tornado shelter door is damaged in a tornado, many experts warn the shelter may no longer be safe. The door of the Granger ISS is replaceable if damaged which is a unique feature on its own. However, Granger Plastics Company offers a separate warranty on the door of its unit to its customers. If the door of your Granger ISS is damaged in a verifiable tornado Granger Plastics Company will make sure it is replaced at no additional cost to the homeowner.
  • The Granger ISS is guaranteed not to float! Granger Plastics works with a variety of qualified installers for self-installation or also offers turnkey pricing including full service installation. Any shelter installed by an approved installer is guaranteed not to float!


Granger Plastics Company is an internationally recognized rotational molding company specializing in superior design and manufacturing. Granger has produced custom products for a wide variety of industries including aerospace, medical, agricultural, material handling and many more. With full manufacturing capabilities, Granger is a rotational molder able to carry an idea from inception through design, manufacturing and order fulfillment.