Constructability—Resistance to the Effects of Weather During Construction
Waterproofing construction takes place outside in a wide range of environmental conditions. Temperature and humidity vary considerably from one location to another. While work should be scheduled for periods of dry weather, unexpected precipitation may occur not long after waterproofing installation.
Variations in temperature and humidity during installation affect the cure and application characteristics of some cold liquid-applied membranes. Cold temperatures will reduce the workability of hot liquid – applied materials and may make some single ply materials less flexible and more difficult to install. Hot temperatures may make waterproofing slide on some vertical substrates. Resistance to weather effects during installation is often not directly addressed in material specifications. Refer to Table 4 for a review of standards.
Meeting the requirements of the low temperature flexibility and impact (brittleness) tests for single ply membranes provide a reasonable assurance that these products can be handled without damage in less than arctic conditions.
Apart from a test that measures crack bridging of an installed membrane at low temperatures, standards for liquid-applied materials lack tests that relate to the installation characteristics of products at extremes of temperature or humidity.
The conditioning for cold liquid-applied materials typically includes an initial period at standard conditions or at room temperature for a duration of 7, 14, or 21 days, depending on the test method. Following this initial conditioning at moderate conditions, there is a period of one, two, or three weeks of oven curing at 23°C (73°F) or 70°C (158°F) depending on the test method.