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III. SEALANTS
The best barrier, drainage and diversion
systems will not work if the transition joints
are not properly installed. The majority of the
failures are due to faulty joint installation or
use of the wrong sealant.
COMMON SEALANT COMPOSITIONS AND
USES
Acrylics:
Factory mixed materials polymerized from
acrylic acids.
These are used frequently in remedial
preparation work before the application of
acrylic-based waterproofing coatings. They are
available in brushable or trowel grades for use in
preparing small cracks in substrates. Acrylic base
sealants do not require primers and need minimal
surface preparation.
These have low movement capability. Do not
use acrylic sealants in high-movement,
vehicular and/or pedestrian joints or
continuously submerged joints.
Butyls:
Sealants produced by polymerization of
isobutylene and isoprene rubbers.
These are the oldest technology in sealants. New
technological advancements in better performing
sealants have now limited their use to glazing
windows or curtain walls with minimum
movement.
They have good adhesion and weathering
capabilities. Butyls are easy to install, they are