Building Design and Construction Handbook - Merritt - Ventech!

BUILDING MATERIALS 4.97
W. D. Kingery, H. K. Bowen, and D. R. Uhlmann, ‘‘Introduction to Ceramics,’’
John Wiley & Sons, Inc., New York.
G. S. Brady and H. R. Clauser, ‘‘Materials Handbook,’’ 13th ed., and J. H.
Callender, ‘‘Time-Saver Standards for Architectural Design Data,’’ McGraw-Hill
Publishing Company, New York.
ASPHALT AND BITUMINOUS PRODUCTS
Asphalt, because of its water-resistant qualities and good durability, is used for
many building applications to exclude water, provide a cushion against vibration
and expansion, and serve as pavement.
4.80 ASPHALTS FOR DAMPPROOFING AND
WATERPROOFING
Dampproofing is generally only a mopped-on coating, whereas waterproofing usually
is a built-up coating of one or more plies. Bituminous systems used for dampproofing
and waterproofing may be hot applied or cold applied.
ASTM D449, ‘‘Asphalt Used in Dampproofing and Waterproofing,’’ specifies
three types of asphalt. Type I, a soft, adhesive, easy-flowing, self-healing bitumen,
is intended for use for underground construction, such as foundations, or where
similar moderate temperature conditions exist. The softening point of Type I may
range from 115 to 140�F. Type II may be used above ground; for example, on
retaining walls or where temperatures will not exceed 122�F. The softening point
of Type II may range from 145 to 170�F.
D449 asphalts are suitable for use with an asphalt primer meeting the requirements
of ASTM D41. In construction of membrane waterproofing systems with
these asphalts, felts should conform to ASTM D226 or D250, fabrics to D173,
D1327, or D1668, and asphalt-impregnated glass mats to D2178.
For cold-applied systems, asphalt emulsions or cut-back asphalt mastic reinforced
with glass fabric may be used. ASTM D1187 specifies asphalt-based emulsions
for protective coatings for metal. D491 contains requirements for asphalt
mastic for use in waterproofing building floors but not intended as pavement. The
mastic is a mixture of asphalt cement, mineral filler, and mineral aggregate. D1668
covers glass fabric for roofing and waterproofing membranes.
4.81 BITUMINOUS ROOFING
Hot asphalt or coal tar are used for conventional built-up roofing. The bitumens are
heated to a high enough temperature to fuse with saturant bitumen in roofing felts,
thus welding the plies together. The optimum temperature at the point of application
for achieving complete fusion, optimum mopping properties, and the desirable interply
mopping weight is called the equiviscous temperature (EVT). Information
on EVT should be obtained from the manufacturer.