TM 5-852-9/AFR 88-19, Vol. IX
causes common caulking compounds to become brittle and lose their cohesion and adhesion. Caulking
materials which can maintain flexibility with permanent cohesion and adhesion at -60E F should be used to
caulk or seal joints of precast concrete panels and metal roofing, around window and door frames, and in
similar areas. Some sealants which meet these criteria are: butyl, polybutene, and polyisobutylene based
sealants; single compound polysulfides, polyurethanes and silicones; and two- component polysulfide and
polyurethane based sealants. For additional information on caulking materials and practices, see TM 5-805-6.
2-7. Exterior doors.
a. Exterior personnel doors. Exterior personnel doors are normally free from frost buildup unless there
is high humidity within the building. Vestibules or arctic entrances should be provided in particularly high-
humidity buildings and windy areas. Typical high-humidity areas are laundry and dry cleaning plants,
restaurants, dormitories, swimming pools, kitchen areas in mess halls, etc. Because of high winds and extreme
cold, doors located on the prevailing windward side of the building should have special protection
(windscreen or baffle) in addition to arctic entrances which are discussed in paragraph 2-10a, this chapter.
Wind screens, baffles, or heavy bumper stops mounted on steel posts should be provided to protect the doors
and hinges from damage and to prevent injury. For energy conservation reasons, arctic entrances are advised
at all major personnel doors. For exterior use, metal doors and frames are sturdier, will look better longer,
are better insulated, and will retain their shape better than wooden doors and frames. Both doors and frames
must be insulated and weatherstripped, and should have an integral thermal break. Seams in doors should be
sealed (continuously welded and ground smooth). Many metal doors have the outside skin directly attached
to the inside. This type of door is unacceptable because the inside surface efficiently collects heat, which the
metal edge then conducts to the outside surface which dissipates it efficiently. When wooden doors are used,
they should be solid-core wood stave to provide maximum insulation and warpage resistance. In the arctic,
temperatures may range from an inside door surface of 60EF to an outside door surface of -60EF. Exclusive
use of insulated metal doors and frames is highly recommended.
(1) Weather-stripping. The entire perimeter of all exterior doors should be weather-stripped with
adjustable cold weather neoprene or butyl rubber in extruded aluminum holders. This type of weather-
stripping retains its flexibility at -60EF. Spring-type or interlocking metal weather-stripping should not be
used because they lack durability, particularly because snow or ice clogging can result in mechanical damage.
Metal weather-stripping should not be used because it will form a through-metal connection between interior
and exterior and ice up quickly.
(2) Thresholds. Thresholds should be hardwood or metal with integral thermal breaks to minimize
cold penetration. Set the threshold in sealant.
(3) Locks. On doors with weather-stripping, cylinder locks or latches should be installed with center
line of lock or latch 5 inches from edge of door. Personnel will be able to avoid skinned knuckles, and operate
knobs easily while wearing mittens and gloves if this 5-inch distance is maintained. Mortise locks or latches
should have lever handles to provide more clearance for hands.
b. Overhead doors. On shop and warehouse buildings where large doors are required, sectional
overhead doors should be used. Standard steel sectional doors consisting of sections fabricated from steel
panels with a foamed-in-place polyurethane core are available from several manufacturers. The outside and