Bulletproof walls are a vital part of any bulletproof system. After all, inch-thick acrylic windows and stainless-steel counters, cash-trays, and frames aren’t worth much if they’re bolted to counters, walls, or doors that couldn’t even stop a shot from a .22 plinker.
Bear in mind that when most people say “bulletproof,” they don’t really expect something to be entirely impervious to bullets. Tanks and bunkers, after all, look like tanks and bunkers. What people commonly call “bulletproof” is really “bullet resistant.” Such materials are tested and rated by independent agencies, who verify that the material can stop three shots from a .357 Magnum, or five from an AK-47, or so on. To these standards, some materials are natively bulletproof, such as a 2-inch thick steel door or thick poured concrete. But, in most cases, people need to rely on existing or easily constructed stud walls, wooden doors, and counter tops. These can become bulletproof walls by backing them with layers of 1/4- or 1/2-inch bullet resistant fiberglass.
BUILDING BULLETPROOF WALLS
The key to a bulletproof wall is bullet resistant fiberglass panels. Fiberglass is a two-part laminated material. At the heart of a fiberglass panel is a a mesh of synthetic para-aramid fibers (a super-tough, fire-proof cousin to nylon). DuPont™ Kevlar® fiber is one famous brand name for para-aramid fiber cloth.
Lay down layers of this woven fiberglass cloth in a thick mat, saturate that mat with synthetic resin, then squeeze and heat it in an industrial press until dry. The result is a hard, dense, rigid panel. When a bullet strikes the panel’s hard surface, the bullet deforms and the laminated layers of the panel accordion apart. This absorbs the bullets energy, but does not permit it to pierce through the panel: The synthetic mesh net catches and deflects the bullet. A bullet resistant panel just 1/4-inch thick can stop at least three 9mm bullets, fired dead on from just a few feet away.
Contractors looking to build bulletproof walls start by framing a standard stud wall. They mount these bullet resistant fiberglass panels to the studs, making sure to double-over all seams with additional strips of fiberglass. The contractor then mounts drywall or paneling on top of the fiberglass. The resulting bulletproof wall can be finished just like any conventional wall–painted, wallpapered, decorated with framed landscapes or advertising. To all passers-by, the bulletproof wall is indistinguishable from any standard room divider.
DuPont™ and Kevlar® are trademarks or registered trademarks of E.I. du Pont de Nemours and Company.