34 / 150
28
SEALANT APPLICATIONS
Correct
Incorrect
Backer
rod
properly
inserted. Mortar cut back
to provide uniform and
proper joint depth.
Irregular depth creates
unequal stress on sealant =
cohesive and adhesive
failures.
Remove
the
mortar,
provide an evenly deep
joint and install a backer
rod.
Bondbreaker tape elimin-
ates adhesion of the sealant
to the back of the joint.
No bondbreaker, sealant
adheres to back of the
joint, thus creating a
cohesive
tear
when
movement occurs
The
bondbreaker
increased width at the
base increasing the
sealant’s
ability
to
compensate for greater
movement.
Sealant can only com-
pensate for movement at
the narrowest point. If
the movement exceeds
the sealant’s limitation,
a cohesive tear will
develop.