Wednesday, February 24, 2016; 11:00 AM - 12:00 PM Eastern
Participants are eligible for one AIA LU credit.
How often can a Single Wythe CMU building be repainted before coating issues are apparent? One key factor that needs to be considered when answering this question is how much the water vapor permeance of the coating system decreases as coats are added. This webinar is the first of a two-part series on the permeance of coatings applied to building exteriors. It addresses what water vapor permeance is; the second webinar in this series discusses why it matters. The following topics are discussed in this Part 1:
• The definition of permeance, how it is measured in the laboratory and its various units
• Differences between the two ASTM standards used to determine permeance (ASTM E96 and D1653)
• The relationship of coating permeance and thickness
• Categorization of building paint systems as impermeable, semi-permeable, and permeable
• Can the water vapor permeance of a paint system already in place be determined?