Comparative Study of Water Vapor Transmission Ratings and Material Properties of Different Waterproofing Systems

摘要

Maintaining optimum moisture levels within a structure has become a critical objective in both above- and below-grade construction design. Moisture damage is a major contributing cause of unhealthy indoor environments, mildew, and fungus that all contribute to "sick building syndrome." Failure to effectively regulate moisture within building structures results in corrosion of steel reinforcement in concrete and beams, rotting of timber structures, swelling of plasterboards, electrical hazards due to short circuits of power points, blistering and peeling of paint, efflorescence of masonry, rotting of wood floors, mildewing of carpet, and invasion of termites. It also makes it more difficult to control heating and cooling. The role of waterproofing/vaporproofing materials is to protect building structure and aesthetic integrity by providing a barrier to the movement of water (liquid as well as vapor) from passing into or out of a structure. Waterproofing and vaporproofing are complimentary to each other and complete moisture protection of a building cannot be achieved by just waterproofing while ignoring the vapor infiltration.