Page 19 - Construction Waterproofing Handbook

CHAPTER 1

WATERPROOFING PRINCIPLES—

THE BUILDING ENVELOPE

INTRODUCTION

Since our beginnings, we have sought shelter as protection from the elements. Yet, even
today, after centuries of technological advances in materials and construction tech-
niques, we are still confronted by nature’s elements contaminating our constructed shel-
ters. This is not due to a lack of effective waterproofing systems and products.
Waterproofing problems continue to plague us due to the increasing complexity of shel-
ter construction, a disregard for the most basic waterproofing principles, and an inability
to coordinate interfacing between the multitude of construction systems involved in a
single building.
Adequately controlling groundwater, rainwater, and surface water will prevent dam-
age and avoid unnecessary repairs to building envelopes. In fact, water is the most
destructive weathering element of concrete, masonry, and natural stone structures. Water
continues to damage or completely destroy more buildings and structures than war or
natural disasters. Water and moisture infiltration is also responsible for mold formation
and the related health issues of building occupants.
Waterproofing techniques preserve a structure’s integrity and usefulness through an
understanding of natural forces and their effect during life-cycling. Waterproofing also involves
choosing proper designs and materials to counter the detrimental effects of these natural
forces.
Site construction requires combining numerous building trades and systems into a
building skin to prevent water infiltration. Our inability to tie together these various com-
ponents effectively causes the majority of water and weather intrusion problems. Actual
experience has shown that the majority of water intrusion problems occur within a rela-
tively minute portion of a building’s total exposed surface area. An inability to control
installation and details linking various building facade components that form the building’s
exterior skin creates the multitude of problems confronting the design and construction
industry.
While individual waterproofing materials and systems continue to improve, no one
pays attention to improving the necessary and often critical detailing that is required to
transition from one building facade component to the next. Furthermore, we seem to
move further away from the superior results achieved by applying basic waterproof-
ing principles, such as maximizing roof slopes, to achieve desired aesthetics instead.
There is no reason that aesthetics cannot be fully integrated with sound waterproofing
guidelines.

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