Keeping Schools Dry And Comfortable
PHOTO © CANDYBOX IMAGES/SHUTTERSTOCK
Moisture infiltration can cause significant damage to your schools. Resulting mold, mildew and water stains are unappealing at best and dangerous at worst. In addition, insulation is not only subject to damage from moisture infiltration, but inadequate insulation accounts for greater energy consumption and, therefore, higher-than-necessary energy bills.
Adequate and appropriate waterproofing and insulation keeps heat (or cold) in and moisture out. Here, the experts present common issues they see in the field, along with sound advice for ensuring learning environments that are dry and have stable temperatures.
Common issues
Waterproofing and insulation go together like peas in a pod: they serve two different functions, but together, they provide a system. “Waterproofing keeps water out, but the location of insulation is often related to the position of the waterproofing, so you need the thermal barrier to keep a building cool or warm, and you need waterproofing to keep water out of the building envelope,” says Thomas W. Hutchinson, AIA, FRCI, RRC, principal of Hutchinson Design Group, Ltd., Barrington, Ill., a full-service architectural firm specializing in roof system design, forensic investigation, roof system failure expert witness work, building envelope and moisture intrusion concerns.
1. Lack of communication: The first issue Hutchinson sees is a lack of communication between architects and designers and manufacturers and contractors. “I’m a firm believer that architects design, manufacturers produce and contractors install,” he says. “As a result, architects and designers have very little knowledge of systems and materials. They rely way too much on contractors and manufacturers to work it out.” If there was greater communication between the groups, plans could be drawn and specifications written more accurately and more specifically.
Take the intersection between a roof and wall for example, says Hutchinson. It should be specified how the roofing membrane ties into the air vapor retarder, which is installed first (the roof or the wall), who is responsible for coordinating the installation and who is responsible when the joint fails. “Design haunts installation,” he sums, and, with solid communication in planning, it doesn’t have to be that way.
2. Having poor air barrier tie-ins: Continuing with the idea of intersections, no one takes responsibility for them, says Samir Ibrahim, director of Design Services for Carlisle SynTec Systems, a roofing system manufacturer based in Carlisle, Pa. They include the roof, building envelope, termination around windows, the junction of the roof to the walls, and the air barrier down to the foundation. He recommends paying strong attention to them for tight and dry facilities, especially when replacing roofs, which get replaced multiple times during a school’s lifetime.
3. Lack of product knowledge: Hutchinson becomes frustrated when architects write performance-based specifications, intimating that it’s because they don’t know the products. The result? He sees products at the building site that are incompatible, which cause construction delays. “Let’s say you’re installing waterproofing on concrete,” he says. “You may be working with an oilbased release agent that may not even stick. Unfortunately, I don’t ever see this huge lack of knowledge ever changing.”
4. Lack of insulation: “There is a huge energy loss when a single layer of insulation is installed,” says Ibrahim. For example, he often sees R24 insulation being specified in one layer. He acknowledges that the initial benefit is up-front cost savings. However, it also creates an energy consumption increase of 14 to 15 percent. He recommends specifying R24 insulation in two layers, which costs a little more up front, but saves on energy consumption in the long run.
5. Being minimum code compliant: “Codes are design as minimum standards,” says Ibrahim, “meaning that you can’t do it any worse than that. They are a threshold, but they end up becoming the standards.” He recommends going above code to achieve a high-efficiency school, including paying attention to the insulation and how it’s installed, including using multiple layers and staggering joints.
6. Falling victim to “green washing”: Ibrahim indicates school administrators are sometimes under the false impression that a white roof is the greenest option. “You hear about how, in the single-ply industry, a white roof reduces the heat island effect and saves energy,” he explains. “This is true — depending on your geographic location. A white roof gives the symbolic impression that a district is sustainability concerned and is jumping on the green movement. But, in truth, when you rely on heating more than cooling, there are no dividends in a white roof.” More specifically, he indicates that a darker color membrane may pay greater dividends in cold climates, and a highly reflective membrane can actually work against schools in cold climates in terms of moisture condensation, which can result in mold.
Expert advice
“It’s amazing how many people who know nothing about roofs work on them,” says Ibrahim. This statement emphasizes the value of this article — an opportunity for facility managers and others to learn more about waterproofing and insulation to protect their facility investments. To that end, here’s some sage advice from the experts.
1. Put service life ahead of LEED points: “Sustainability is all about long-term service life,” says Hutchinson. “If I have a roof system that still works after 30 years, I should get a LEED point for it. However, there’s no component in LEED for long-term service life. So forget about LEED points and purchase something that’s proven to last rather than purchasing the latest trend.”
2. Do it right the first time: Schools cost millions of dollars to build and are designed to last for a hundred years, so it only makes sense to build them right in the first place. “I see million-dollar facilities built with 10-year roof systems,” says Hutchinson. “That’s ludicrous. Insulation works every day, year after year, so why would you skimp on it? If you use X amount of insulation, it may be more than standard now, but less than standard in the future. And, when have you ever seen energy costs go down? You haven’t. They’re going to keep going up.”
3. Work with a qualified roof consultant and/or architect: Whether doing new construction or a major renovation, it’s important to hire someone who’s knowledgeable and can write specific, detail-oriented specifications. “I have some specs that are 30 pages,” says Hutchinson. “Sometimes that’s what’s required to ensure that all the building components — duct work, HVAC, masonry, for example — are understood, field verified and integrated into the solution. There’s no room for ‘I don’t know.’”
This article originally appeared in the School Planning & Management October 2013 issue of Spaces4Learning.