Waterproofing and Insulation

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.

Weatherizing 101

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 building’s lifespan.”

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 installation.

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.

Insulation 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

Naturally, choosing the right building products is important to constructing waterproof and well-insulated facilities. But the experts agree that there’s more to the equation.

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 maintenance.

Did You Know?

ASHRAE 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 ASHRAE 90.1.

A Valuable Resource

The 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.”