Subframe. A matching subframe and outer frame are
recommended to resist bomb attacks. Subframes are mounted in the
concrete form work prior to pouring concrete. Anchorage is
embedded with welded anchor studs. After pouring the walls,
outer frames and glazing can be installed in the subframes. A
blast consultant must analyze and design a subframe and its
anchorage. If an embed is not used, construction of concrete
requires higher than normal quality control.
Removable Stop. The removable stop is a component of
the frame that holds the glazing in place. The purpose of the
removable stop is to allow installation of the glazing into the
frame. Therefore, best security integrity against a forced entry
attack is achieved when the removable stop is positioned on the
interior side of the glazing, that is, the protected side. The
removable stop is held in place with fasteners, anchor bolts, or
Fasteners. Fasteners hold the removable stop in place.
For protection against forced entry attack, glazing fasteners
should be installed on the protected side of the window.
Glazing Tape, Sealant and Setting Blocks. Glazing
tape, sealant, and setting blocks provide a cushion between
frame material and glazing to prevent glass breakage from
thermal, settling, and wind loads of a building. Glazing tape
and sealant support a glazing laterally. They set and maintain
the face clearance between a frame bite and glazing face.
Setting blocks set and maintain the edge clearance of a glazing.
These materials are in direct contact with a glazing or
its edge. Compatibility with the glazing is an important
consideration when selecting glazing tape and setting block
materials. To avoid glazing contamination, use only manufacturer
recommended glazing tape and setting block materials.
a) Sealant. A sealant is in direct contact with the
glazing material. A sealant provides resistance to environmental
degradation effects around the edge of a glazing. Security
laminates should be wet sealed to obtain optimum performance in
security applications. When installed, the sealant should be
tooled to shed water.
Tests have shown that wet sealed glazing laminates tend
to anchor failed glazing to the frame when subjected to blast
overpressure. This phenomenon can reduce the risk of glass