Page 109 - Construction Waterproofing Handbook

2.72 CHAPTER TWO

FIGURE 2.93 Termination detailing for clay system.
(Courtesy of Cetco Building Materials Group)

FIGURE 2.94 Termination detailing for clay system
using reglet. (Courtesy of Cetco Building Materials
Group)

As previously discussed, soils have characteristic capillary action that allows the
upward movement or migration of water vapor through the soil. Beginning as water and
saturating the soil immediately adjacent to the water source, the capillary action ends as
water vapor in the upper capillary capability limits of the soil.
Vapor barriers prevent upward capillary migration of vapor through soils from pene-
trating pores of concrete slabs. Without such protection, delamination of flooring materi-
als, damage to structural components, paint peeling, mildew formation, and increased
humidity in finished areas will occur. Vapor barriers can also prevent infiltration by alka-
line salts into the concrete slab and flooring finish.
Vapor barriers are produced in PVC, combinations of reinforced waterproof paper with
a polyvinyl coating, or polyethylene sheets (commonly referred to as visquene).