Preventing Catastrophic Failure

“One of my favorite school roof stories is about a roof we completed 10 years ago,” begins Dave Landis, southeast region sales and technical manager for Elk Grove Village, Ill.-based Petersen Aluminum Corp., which produces metal roofing, wall panels and more. “When the roof was about four years old, I received a call from the school’s facility manager, who said, ‘I have a problem: We have a hole in the roof. Let me tell you how it happened.’ Turns out, the school has a rocket club. You can already see where this is going.”

Landis recounts the story of a rocket that went awry, striking the middle of the metal roof at an angle so that it left a quarter-size hole and a black mark. “We came up with an acceptable way to repair the hole and clean off the black mark so that it wasn’t noticeable,” he concludes.

The story’s lesson is that man-made (or, in this case, student-made) roofing challenges can be successfully repaired. That’s all good and well, but what happens when school roofing challenges are caused by an act of Mother Nature? Well, because her fickle mood ranges anywhere from slightly irritated to downright angry, the best way to protect a roof is to maintain the upper hand. Here, roofing professionals share their insights on preventing catastrophic roof failure.

First things first: Design
The first way to get the upper hand against Mother Nature is to design and install the roof system correctly.

Design: “With proper engineering and design, you can significantly reduce the possibility of catastrophic failure in the event of Mother Nature’s tornadoes and hurricanes,” says Brian Lambert, director of Products & Systems for Cleveland-based The Garland Company, Inc., which offers a range of modified and built-up roofing (BUR) systems. “For example, there are calculations that are done based on the wind zone where the school is located, so the engineering requirements that dictate how the roof is to be fastened and the edge metal attached is different for a coastal location versus an inland location.”

Ken Gingerich, manager of Project Review and Design for Carlisle, Pa.-based Carlisle SynTec Systems, which manufactures single-ply roofing solutions, agrees, similarly observing that a roof in a northern environment is subjected to different weather than a roof in a desert environment. “So choosing the material that’s appropriate to the climate zone helps mitigate problems.”

Designing with the right materials for the application includes paying attention to the little things. Lambert, specifically, indicates that flashings and details are the most important part of a roof: “When a roof leaks, it leaks where the roof ends, such as at flashings, drains and curbs, so properly designing and installing them is critical.”

Why the hoopla about design? Schools are high-end construction, and the interior finishes are built to last for 50 to 75 years. “Because you have a building constructed to endure, the roof should be part of that longevity, protecting the interior,” says Gingerich.

Code: Lambert indicates that he believes it’s rare for a roof to be completely blown off. Instead of such catastrophic damage, he says it’s more common to see damage from wind and hail storms. Damage begins at a corner or perimeter where there’s wind uplift. Most damage can be prevented by simply following code, especially for roof edges. “An EF5 tornado isn’t going to be prevented by the best roof from tearing it off,” he notes, “but following code provides peace of mind that it’s designed and constructed to not come off.”

Codes are written to designate minimum requirements. Gingerich encourages his clients to exceed those requirements. “I tell school administrators that they don’t have to settle for minimum,” he says. “There are paybacks in terms of energy savings and long-term performance to be realized by going above what’s required. On the other hand, there also is a line indicating when you’ve spent more money than you’ll recover, and you have to find that line.”

To indicate the importance of building codes, Landis observes that they have become more stringent in Florida. “Building owners and authorities having jurisdiction in school construction have realized how accurate and pertinent the new building codes are,” he says. “As a result, they’re incorporating Florida’s requirements throughout the Coastal United States.”

Installation: “You can’t predict what Mother Nature will deliver next,” says Gingerich. Because this is true, and because no one wants to experience catastrophic roof failure, proper installation is critical. Landis drives home the point: “One of the things we’ve learned from the hurricanes we experienced in the south from 2004 to 2012 — particularly on metal — is, if it’s installed correctly, whether it’s in Miami or Charleston, S.C., the roof is not coming off.”

The experts note three specific areas that need attention when a roof goes on. The first is ensuring the clip anchor system for the panels is installed at the correct spacing for the specific project to accommodate wind load. The second is ensuring the flashing anchor attachments are properly fastened and that there is applicable heavy gauge support steel to attach the flashings to the roof, particularly at roof edges and corners. The third is ensuring the accurate installation of the metal edging. “If you have a drip-edge roof, and the metal edging is neither the right gauge nor installed according to code,” says Gingerich, “wind is allowed to get in the roof system, and the system can peel. When exposed to peel, roofs come off very easily.”

Lambert supports the importance of installation by indicating that supervision and inspections are required as construction progresses. “Is Mother Nature the enemy?” he asks. “Sure. But, a lot of times, man can also be the enemy and, if we are able to minimize errors, we have a much greater chance of success.”

In good time: Maintenance

The second way to get the upper hand against Mother Nature is to keep roofs well maintained.

“We are big fans of roof inspections and finding problems before a leak develops,” says Lambert. Often, cash-strapped school administrators note that, because the roof isn’t leaking, they’ll pass on inspections to save some money. Lambert counters that when the roof isn’t leaking is exactly the time to check for small problems that can be alleviated before they become big problems.

Depending on the type of roof covering your school, you’ll want to inspect anywhere from quarterly to yearly. “Have facilities folks walk the roof, removing any debris that the students have thrown on it,” says Landis, who recommends a yearly inspection, “such as stones, sneakers and balls.” You’ll also want to remove debris placed there by Mother Nature, such as leaves and branches from overhanging trees, which are notorious for blocking drains.

Repairs: And, of course, if issues are discovered during the inspection, such as ponding water, loose caulking or flashings that are starting to lift, they’ll need to be addressed immediately. “When resolved regularly,” says Gingerich, “these minor repairs add longevity to the roof system.”

Before tackling those issues, however, Landis cautions facilities managers to contact the roof contractor and manufacturer to ensure that the work needing done does not void the warranty from either the contractor or manufacturer.

Cleaning: Hand in hand with inspections is cleaning the gutters. “A simple cleaning of the gutters once a year goes a long way to ensuring roof performs as it’s supposed to,” says Landis.

From engineering and design to maintenance and repair, respecting the investment made in a school roof is the best way to ensure that it’s prepared to stand up to the worst that Mother Nature can throw at it, thus preventing catastrophic failure.