THE BUILDING ENVELOPE.

The building envelope is equivalent to the skin of a building. In essence, a structure must be enveloped from top to bottom to prevent intrusion from nature’s elements into interior spaces and to protect the structural components from weathering and deterioration.

Envelopes complete numerous functions in a building’s life cycle, including

● Preventing water infiltration
● Controlling water vapor transmission
● Controlling heat and air flow, into and out of interior spaces
● Providing a shield against ultraviolet rays and excessive sunlight
● Limiting noise infiltration
● Providing structural integrity for the façade components
● Providing necessary aesthetics
● Preventing of mold formation and growth

While the main purpose of any building envelope is to provide protection from all elements, including wind, cold, heat, and rain, this book concentrates on the controlling of water and leakage for all construction activities including the building envelope. Making a building envelope waterproof also provides protection against vapor transmission and serves to prevent the unnecessary passage of wind and air into or out of a building, assisting in the controlling of heating and cooling requirements. Before considering each specific type of waterproofing system (e.g., below-grade), some basic concepts of waterproofing and how they affect the performance of a building envelope are important to understand.