Page 226 - Construction Waterproofing Handbook

CHAPTER 4

RESIDENTIAL WATERPROOFING

INTRODUCTION

Here is a simple truism that sums up the current state of waterproofing in residential con-
struction: Homebuilders use caulk, not sealant. If it is not available at the local building sup-
ply store, it is not going to be used during construction; therefore, most homebuilders do not
recognize the need for sealants in properly finishing a building envelope to be waterproof.
Residential waterproofing practices are no different from any of the commercial prac-
tices and principles presented throughout this book. Unfortunately, very few homebuilders
and remodelers recognize or are aware of good waterproofing practices, and typically, the
only time they even consider using a waterproofing product is when a house includes a
basement. Even then, many confuse damproofing with waterproofing or have no idea how
to install a waterproofing system properly. Again, if they cannot run down to the local
building supply store and buy it, they will use something else or go without.
One has only to look in any phone book or online for remedial residential waterproof-
ing contractors to realize that the large number of waterproofing companies obviously
means that water intrusion into residential construction is a big market. Homebuilders usu-
ally not only ignore the need for waterproofing systems but also totally ignore the 90%/1%
and 99% principles presented in Chap. 1.
Ask just about any subcontractor working on a residential site about how he or she is
going to transition his or her systems into another subcontractor’s work to prevent water
and moisture intrusion, and most assuredly you are going to get a blank stare. The only
reason that residential construction does not appear to have the substantial leakage and
water infiltration normally associated with such negative practices is that home construc-
tion for the most part is relatively simple. For example, houses are low-rise structures that
are not subjected to the elements encountered in high-rise structures.
However, on closer examination, it is rare to find a home in which there are no traces
of water or moisture infiltration. Most often this is found in the form of mold or wood rot
rather than in direct water infiltration. Again, this is due to water being shed fast enough
from the exterior skin to prevent major leakage, but still the construction is not sufficient
to prevent water intrusion that leads to mold, wood rot, and damaged interior finishes.
The one major difference between residential and commercial construction is that as
much as 99% of water intrusion, rather than the commercial 90%, is caused by 1% of the
exterior surface area. Thus, in residential construction, the first principle becomes a
99%/1% practice rather than 90%/1%. This is due to the fact that residential construction
uses much simpler facade construction, and leakage is almost always due to inadequate
transitioning between dissimilar exterior finishes.

4.1
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