In parts of the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 where homes do not have basement

Basement

__FORCETOC__A basement is one or more floors of a building that are either completely or partially below the ground floor. Basements are typically used as a utility space for a building where such items as the furnace, water heater, breaker panel or fuse box, car park, and air-conditioning system...

s and construction of storm cellars

Storm cellar

A storm shelter or storm cellar is a type of underground bunker designed to protect the occupants from violent severe weather, particularly tornadoes...

 are becoming rare, storm rooms are gaining popularity as a defense against tornadoes and other storms.

A storm room is a freestanding above-ground room that is fabricated using walls created with layers of Kevlar

Kevlar

Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...

 bonded to a 4 inches (101.6 mm) panel of engineered foam

Foam

-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...

 and sandwiched between two layers of plywood

Plywood

Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...

. The Kevlar acts like a trampoline and bounces back projectiles hurled by the winds from a tornado. A storm room is attached only to the concrete slab of a structure without touching the structural walls, and can be installed in existing structure and well as new construction.