Waterproofing and Insulation
- By Ellen Kollie
- February 1st, 2008
There are two main reasons to keep every campus
facility waterproof and well insulated. The first is for energy conservation: a
tight building uses less energy. The second is to increase a building’s
lifespan, as a leaky building causes materials to degrade. Here’s what you need
to know about specific areas, followed with sage advice from the experts.
When it comes to providing for your building
envelope, attention must be paid to some specific areas, and high-quality
products must be chosen.
Roofing: Roofing insulation can be
either on top of or beneath the roofing membrane. Which is chosen will depend
on what you’re comfortable with, the region in which the facility is built, and
what the contractor is comfortable with.
Insulation is often installed on top of the popular
single-ply membrane-type roofing system. If a leak occurs in this type system,
it’s relatively easy to locate.
Insulation can also be installed on the bottom of
the inverted roof membrane system. “I feel it’s a better system,” said Monica
Armstrong, project manager for Atlanta-based The Facility Group. The drawback
to this system is that leaks may be more difficult to find.
One insulation option is polyisocyanurate, used in
both new construction and renovation, and adaptable with a variety of roof
systems. This high-thermal, closed-cell foam plastic insulation is available in
a range of sizes and offers a high thermal value per inch.
“Because polyisocyanurate is closed cell, it has
attributes that other insulation materials don’t have,” said Jim Whitton,
national sales manager for Portland, ME-based Hunter Panels, which manufactures
polyisocyanurate roof insulation panels. As a result, the product qualifies for
LEED certification credits.
Windows: Windows are a penetration
in a building’s exterior, so it’s critical to seal the joint between the window
system and wall system. “Don’t depend just on caulking or sealants to provide
that barrier,” said Bob Gunning, AIA, project architect with The Facility
Group. “Use a flashing.”
Skylights: If you’re installing
skylights, do your research to make sure you choose a system that’s tested to
withstand wind pressure and the elements. Seal it with flashing and caulk. And,
because it’s a roof penetration, be sure it has a curb that’s high enough to
keep ponding water from getting into the joint.
Doors: Doors can be protected from
inclement weather with weatherstripping, which doesn’t reduce energy costs so
much as it increases comfort. Fortunately, it’s inexpensive and quick to
install. Gunning advises using a compressible weatherstripping around the
doorframe to create a tight seal. Combine this with a sturdy sweep attached to
the bottom of the door itself and/or threshold weatherstripping.
Also, consider installing steel doors, which are
well known for their ability to keep out poor weather. In addition, they’re
long lasting and recyclable.
Building exteriors: Water repellents applied to
a building’s exterior substrate to create long-lasting protection from the
negative effects of weather are becoming more popular. They can be applied to
either existing or new construction, and they work to reduce damage caused by
rain, frost, and pollutants, thus decreasing maintenance costs.
Water repellents are available for use in
formulations that penetrate a broad range of substrates, including
poured-in-place or precast concrete, concrete block, sandstone, granite,
limestone, marble, brick, tile, and wood.
These products can extend the life of substrates by
providing a variety of benefits that include water repellency; UV stability;
reduced efflorescence; water vapor permeability; clear, uniform, neutral
appearance; and reduced freeze-thaw damage.
Below-grade drainage: A sure-fire way to keep a
building waterproof is to keep below-grade water away from the foundation. A
drainage system must be well thought out during new facility planning. When
done correctly, it prevents leaky basements and structural damage.
A drainage product, while not contributing to the
creation of a pretty facility,” noted Jason Covington, general manager of
Wylie, TX-based CCW’s Waterproofing Division, which manufactures a drainage
system, “lends itself well to the green movement in that it increases a
Above-grade waterproofing: Both air and vapor barriers
are above-grade waterproofing products designed for new construction. When
properly designed and installed, they seal a building from air and moisture.
Specifically, a vapor barrier prevents moisture from
entering the cold portions of a building’s envelope, thus reducing the
potential for condensation, which causes both mold and building deterioration.
An air barrier stops mass airflow into and out of exterior walls, thus
preventing water vapor from entering the building envelope.
Barriers are made in a variety of materials and
systems and come with a variety of applications. These materials are not subject to
hydrostatic pressure but are exposed to weathering and pollutant attack.
Exterior wall systems: There is much to choose
from in today’s exterior wall systems. Manufacturers have developed systems
that offer low maintenance, energy efficiency, and durability. For example,
precast wall systems offer a wide range of cladding materials, such as EIFS,
brick, metal, and granite, and are delivered to the job site for immediate
Another example is an insulated concrete form system
(ICF) offering energy efficiency and construction speed. The system features
concrete that is sandwiched between EPS foam in standard-sized sections.
values of ICF walls vary depending on the material and its thickness. Typical
insulation values range from R-17 to R-26, compared to between R-13 and R-19
for most wood-framed walls. The strength of ICF structures relative to lumber
depends on configuration, thickness, and reinforcement. However, ICF walls are
designed as reinforced concrete, having high wind and seismic resistance.
When choosing an exterior wall system, compare
initial cost vs. maintenance cost vs. energy savings of several systems to find
the best fit.
Words of Wisdom
choosing the right building products is important to constructing waterproof
and well-insulated facilities. But the experts agree that there’s more to the
For one thing, getting involved early in the design
process and communicating well throughout it ensures success.
Also, be sure to look at long-term costs as opposed
to just construction costs. With the oil prices continuing to rise,
administrators must consider products that reduce a facility’s overall energy
consumption now and in the future. Therefore, money spent upfront on a higher
R-value is soon recouped through long-term energy savings.
Finally, the experts say, once the facility is
built, maintain it. Even the soundest building materials, like brick, require
Did You Know?
90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings,
provides minimum requirements for the building envelope and systems and
equipment for electrical power, lighting, heating, ventilating, air
conditioning, service water heating, and energy management. One of the
requirements is for continuous insulation to create a weather-tight facility
and thus save energy. In fact, LEED certification requires compliance with
A Valuable Resource
Facility Group’s Armstrong and Gunning recommend a valuable resource for more
information on keeping your campus facilities waterproof and well insulated:
the Whole Building Design Website at www.wbdg.org. “It’s a great source,”
Armstrong noted, “and it’s written by experienced professionals.”