Page 245 - Construction Waterproofing Handbook

5.4 CHAPTER FIVE
Once this study is complete, design calculations must be completed to determine the type,
spacing, and size of joints. Joint types include
● Expansion joints
● Control joints
● Isolation joints
● Detailing joints
Expansion joints. Expansion joints allow for movement in a structure or material that
is caused by thermal expansion or contraction and other inducements such as wind load-
ing or water absorption. Expansion joints are active dynamic movement joints that continue
to move by expansion or contraction. See Fig. 5.2 for a typical masonry expansion joint.
Control joints. Control joints allow for expected cracking due to settling, curing, or sep-
aration in building materials after installation. Interior control joints, including concrete slab
control joints, typically are nonmoving joints and are placed and sized for expected cracking
or shrinkage only. Exterior control joints, such as brick paver joints, provide for settling as
well as movement, the latter due to vehicular or pedestrian loading and expected thermal
movement. These joints require more design work than interior joints, as they will become
dynamic moving joints. Figure 5.3 details differences between expansion and control joints.
Masonry and mortar shrinkage after placement and curing requires that control joints
be placed at appropriate locations. These joints allow for shrinkage and settlement to occur
without affecting an envelope’s performance. Control joint locations should include:
● Areas of change in wall height
● Junctures or transitions at columns or other structural construction

FIGURE 5.2 Expansion joint at a masonry envelope ready for
sealant application.