Page 35 - Construction Waterproofing Handbook

WATERPROOFING PRINCIPLES—THE BUILDING ENVELOPE 1.17
problems. This 1 percent requires much more attention and time by owners, architects, engi-
neers, contractors, and subcontractors to ensure an effective building envelope.
The most frequent problems of this 1 percent occur because of inadequate detailing by
architects, improper installation by contractors and subcontractors, and improper maintenance
by building owners. Typical frequent envelope errors include

● Architects and engineers. Improper detail specifications (90%/1% principle); no
allowance for structural or thermal movement; improper selection of materials; use of
substitutes that do not integrate with other components of the envelope.
● Component manufacturers. Insufficient standard details provided for terminations and
transitions; inadequate training for installers of materials; insufficient testing for com-
patibility with other envelope components.
● General contractors and subcontractors. Improper installations (99% principle); inat-
tention to details; no coordination between the various envelope subcontractors; use of
untrained mechanics to complete the work.
● Building owners and managers. No scheduled maintenance programs; use of untrained
personnel to make repairs; no scheduled inspection programs; postponement of repairs
until further damage is caused to the envelope and structural components.

Manufacturers are now concentrating on making technological improvements in the
materials themselves rather than technological advances, specifically making their products
“idiot-proof.” They realize that meeting industry standards does not correlate with success
in field applications. In reality, products are subjected to everything that can possibly go
wrong, from environmental conditions during installation to untrained mechanics installing
the product. Never are products installed in the pristine conditions of a laboratory. Making
their products with “belt and suspenders” protection increases the likelihood of success, at
least for the individual system—for example, products that no longer require primers, no
mixing of two component materials but now one-part materials, pressure rinse versus
pressure-wash preparation, and 300% elongation rather than 100% to add additional pro-
tection against excess movement or in-place service requirements.
Similar quality advances at the job-site level by contractors to adequately apply the
precautions necessary to protect against the 90%/1% and 99% principles will eliminate the
vast majority of waterproofing problems that now plague the industry.

USING THIS MANUAL

Chapters 1 through 3 of this manual supplement a specific area of the building envelope.
Every component involved in waterproofing envelopes is reviewed in detail for all types of
common construction techniques. Chapter 3 also provided coverage for envelope water-
proofing, including interior applications such as shower stalls and civil/infrastructure
waterproofing.
Chapter 4 has been added in this new edition to highlight the specific concerns when
addressing the building envelope in residential construction and shows the relevant importance