Which of the following describes the type of construction materials most commonly used to build a bank’s exterior walls?

A.
Dense woods fastened with metal bolts and plates

B.
Steel rods encased inside of concrete walls and support beams

C.
Untreated lumber

D.
Steel

Explanation:
B: Risk analysis results help the physical security team determine the type of construction material that should be used when constructing a new facility. Several
grades of building construction are available. The team should choose its construction material based on the identified threats of the organization and the fire
codes to be complied with. The construction material can be fire-retardant and have steel rods encased inside of concrete walls and support beams. This provides
the most protection against fire and forced entry attempts. Facilities for government organizations, which are under threat by domestic and foreign terrorists, would
be built with fire-resistant materials. A financial institution would also use fire-resistant and reinforcement material within its building. This is especially true for its
exterior walls, through which thieves may attempt to drive vehicles to gain access to the vaults.
A is incorrect because dense woods fastened with metal bolts and plates are used in heavy timber construction material, which is commonly used for office
buildings. Combustible lumber is used in this type of construction, but there are requirements on the thickness and composition of the materials to provide more
protection from fire. The construction materials must be at least four inches in thickness. Whereas light frame construction material has a fire survival rate of 30
minutes, the heavy timber construction material has a fire survival rate of one hour.
C is incorrect because untreated lumber is used as light frame construction material, which provides the least amount of protection against fire and forcible entry
attempts. The untreated lumber is combustible during a fire. Light frame construction is usually used to build homes, primarily because it is cheap but also because
homes typically are not under the same types of fire and intrusion threats that office buildings are.
D is incorrect because steel, an example of an incombustible material, provides a higher level of fire protection than the previously mentioned materials but
loses its strength under extreme temperatures, something that may cause the building to collapse. So, although steel will not burn, it may melt and weaken.