Page 261 - Construction Waterproofing Handbook

5.20 CHAPTER FIVE
exposed and within reach of children at schools, horizontal joints subject to ponding
water such as coping stone joints, or joints with numerous changes in direction such as
balustrade joints (Fig. 5.26).
The joint protector must be installed before the joint sealant has cured, to ensure that
the anchor becomes an integral part of the joint. This prevents the anchor from moving
after installation, which can actually damage the joint and permit water infiltration.

Substrate Diversions
If single-sealed joints are to be used on an envelope, substrates that form the joints should be
constructed or manufactured to shed water quickly from the joint and envelope. They should
also be designed to prevent water from traveling laterally across the joints.
Figure 5.27 shows several primary envelope barrier designs that complement joint
effectiveness. These allow joint sealants to be the secondary means of protection against
water infiltration. These designs also provide secondary protection against direct water
infiltration, should a sealant exhibit minor disbonding or adhesion problems along the
joint. Never should an envelope joint be designed that allows water to stand or collect on
the sealant material.

MATERIAL SELECTION

In addition to the elongation properties necessary for the expected movement, the most
important sealant properties are:

FIGURE 5.26 Preformed joint protector is supplied
in rolls and conforms to the joint shape. (Courtesy of
Weathercap, Inc.)