Custom Search
|
|
|
||
 MIL-HDBK-1001/5A
5.2
General Requirements
5.2.1
Felts. Organic felts are
highly vulnerable to
moisture-induced deterioration; use
the more durable fiber glass
felts. Organic felts can, however,
be used in temporary
membranes that are to be removed or
in coal-tar pitch membranes.
5.2.2
Modified Bitumen Flashing. Single-ply modified bitumen
sheets may be used for flashing material.
5.2.3
Compatibility. Check with the manufacturer of built-up
roofing membrane and flashing materials to assure that proposed
roof system and materials are compatible with roof deck, vapor
retarder, insulation, and geographic location.
5.3
Membrane Design Recommendations
5.3.1
Bitumen Slope Limits
SLOPE
BITUMEN TYPE
SOFTENING POINT
(inches per foot
(degrees F (C))
(percent)
135 - 151 (57 - 66)
1/2 (4) or less
Asphalt,
ASTM D 312,
Type I
1/2 to 1-1/2 (4
Asphalt,
ASTM D 312,
158 - 176 (70 - 80)
to 12)
Type II
185 - 205 (85 - 96)
1 to 3 (8 to 25)
Asphalt,
ASTM D 312,
Type III
Steep and
Asphalt,
ASTM D 312,
205 - 225 (96 - 107)
flashings
Type IV
1/4 (4) or less
Coal Tar
Pitch, ASTM D 126 - 140 (52 - 60)
450 Type
I
1/2 (4) or less
Coal Tar
Pitch, ASTM D 133 - 147 (56 - 64)
450 Type
III
Require bitumen manufacturer to provide equiviscous temperature
(EVT) stenciled on every bitumen container or tanker weight bill
to facilitate application at proper viscosity.
5.3.2
Flashing Design Principles.
Good flashing design
requires the following:
a)
Elimination of as many penetrations as practical;
b) Location of individual roof penetrations at least
18 inches (457 millimeters) apart;
18
|
 
|
|
|
||
