Wind-damaged Roof Systems

Wind damage to roof systems is often catastrophic, placing the building users at a life-safety risk, resulting in interior and furnishing damage and suspension of interior operations, loss of revenues, legal ramifications and great costs to repair. Because of my 30 years of experience in the design of roof systems and forensic investigation, I’m often called upon as an expert witness after wind events. In this article, I’ll review a couple wind-event roof failures, the causes of the failures and how they could have been prevented. I’ll also provide recommendations for failure prevention in the design process for new roof systems, as well as for existing roof systems.

1. The concrete roof deck panels deflected more than 3/4 inch, which the design architect should have accounted for if a thorough field investigation was undertaken.

1. The concrete roof deck panels deflected more than 3/4 inch, which the design architect should have accounted for if a thorough field investigation
was undertaken.

The Perfect Storm

How can it be that when roof systems are to be designed for code-required wind-uplift resistance that so many fail in winds well below the design parameters and/or warranty coverage? The answer could be design-related, material or installation; typically, it involves all three.

Architects and some roof system designers are often not as knowledgeable about roof systems as they should be, have little empirical evidence in how all the components work together as a system, and move beyond their abilities (a violation of their standard of care) when designing roofs where specific detailing is required. In addition, manufacturers are all too often
bringing new products to the marketplace that have not been properly vetted in the field and their long-term performance is truly unknown. Unfortunately, the roofing contractor cannot escape any of this. The lack of proper specification and contract document review; failure to review product data, including installation guidelines for new products; poor project oversight and management; and pressure from general contractors often result in installations that are subpar. The result is a “perfect storm” of design, materials and installation that fail under stress.

Consider the following case studies that I have been involved in as a forensic or “expert” witness when litigation was involved.

Coastal Facility

A large aged warehouse along the eastern seaboard was in need of a new roof system. Because the interior was not conditioned, thermal insulation was not required. The existing roof was an asphalt built-up with aggregate surfacing on high-density fiberboard on precast concrete panels 24-inches wide on a steel structure. The northern portion of the building had overhead doors that were seldom closed. On the interior, an aedicule structure (a building within a building) was constructed approximately 65-feet south of the overhead door, which had a ceiling level 5-feet below the roof deck.

2. The thin, flexible 1/2-inchthick high-density board was found to have little, if any, contact with the full-coverage spray-foam adhesive, making uplift extremely easy.

2. The thin, flexible 1/2-inch-thick high-density board was found to have little, if any, contact with the full-coverage spray-foam adhesive, making uplift extremely easy.

The architect who designed the replacement roof system called for the existing BUR roof to be removed down to the precast concrete roof panels. Then a new 1/2-inch 4- by 8-foot high-density wood fiberboard was set in full-coverage spray polyurethane foam adhesive with a 60-mil EPDM membrane fully adhered to the high-density wood fiberboard.

Additionally, the architectural drawings called for rooftop relief vents to be removed and capped over.

Around June 2008, a Nor’easter (an intense rainstorm), coming in from the east off the ocean, swept into the city. This resulted in the new roof system being lifted off the roof deck. Mode of failure was the fiberboard detaching from the precast concrete roof deck.

Investigation revealed several acts and conditions that contributed to the wind damage.

PHOTOS: Hutchinson Design Group Ltd.

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Soft Roll Simplifies Venting

Quarrix Building Products introduces Flex Vent Soft Roll

Quarrix Building Products introduces Flex Vent Soft Roll

Quarrix Building Products introduces Flex Vent Soft Roll, a lightweight, low-profile rolled ridge vent that will simplify venting for roofing contractors. Manufactured from non-woven and non-wicking polyester matting, the product is easy to install with no complicated fittings, wrapping or connectors. The rolled ridge vent is well suited for metal and asphalt and virtually disappears on the roof when installed. Quarrix Flex Vent is 10 1/2-inches wide, 3/4-inch thick and 20-feet long and includes 1 3/4-inch coil nails.

New CertainTeed Webisode Highlights Attic Ventilation

CertainTeed’s fourth webisode in the 2013 Living Spaces Facebook Home Makeover Video Contest, featuring the Bielfelt family of Mentor, Ohio, dives deep into the importance of superior weather-resistance and proper ventilation as part of a healthy whole-home system.

CertainTeed 5-Star Green and Master Shingle Applicator contractor, RJK Construction Co., of Willoughby, Ohio, installs Winterguard and DiamondDeck roofing underlayment as well as CertaWrap, CertaTape andCertaFlash housewrap products in the webisode to create a water- and wind-tight barrier to protect the century-old home’s original structure.

Grand prize winner of the $75,000 exterior makeover contest, the Bielfelts are the subject of a series of CertainTeed Living Spaces webisodes documenting the renovation of their 100-year-old home. The series follows the family, along with local contractors, from the planning stages of the renovation through its completion.

In the first few webisodes, the homeowner selected multiple products, including Cedar Impressions and Monogram siding, Restoration Millwork trim, EverNew decking and railing, Bufftech fence and Landmark Pro roofing. The homeowner also utilized the CurbAppeal iPad app, ColorCoach virtual swatch book and ColorView design tool, which allows homeowners to visualize how products will look on their home.

To view all of the webisodes, music videos and video entries from the 2013 $75,000 Exterior Living Spaces Home Makeover, visit the CertainTeed Living Spaces Facebook page or YouTube channel.

Ridge Vent Requires Fewer Fasteners

With the new improved design of Metal-Era's Hi-Perf Ridge Vent, much of the product will come preassembled, reducing the number of fasteners needed by up to 67 percent and decreasing installation times by up to 50 percent.

With the new improved design of Metal-Era’s Hi-Perf Ridge Vent, much of the product will come preassembled, reducing the number of fasteners needed by up to 67 percent and decreasing installation times by up to 50 percent.

With the new improved design of Metal-Era‘s Hi-Perf Ridge Vent, much of the product will come preassembled, reducing the number of fasteners needed by up to 67 percent and decreasing installation times by up to 50 percent as compared to other multi-component products on the market.

Engineered to individual job requirements, the patented, unique design of the Hi-Perf Ridge Vent is built to withstand winds up to 120 mph, and it’s backed by the only ventilation and wind warranty in the industry. The all-metal construction will not compress under stress, making it weather-proof and bug-proof. It has also passed water infiltration test TAS 100(A), ensuring a weather-proof vent.

The Hi-Perf Wind and Ventilation Warranty is available on all Metal-Era manufactured Hi-Perf ventilation systems. It guarantees that Hi-Perf systems:

  • when designed according to the Metal-Era calculated NFA will provide proper ventilation for the project
  • will withstand winds of up to 120 miles per hour
  • will be free of defects in Metal-Era supplied materials

The warranty covers repair or replacement of the system for 20 years or the lifetime of the roof on which it was originally installed, whichever comes first.

The product’s unique design allows for covers to be manufactured in 24-gauge steel, 0.040-, 0.050- and 0.063-inch aluminum. Cover plates provide a cleaner, more aesthetically pleasing appearance. Guarantees required exhaust airflow at the ridge to help prevent heat buildup and moisture accumulation underneath the roof covering, thereby increasing the life of the roof. The Ridge Vent is engineered to individual job requirements; this ensures that it will perfectly fit each roof condition.

The all metal construction withstands heavy snow loads and will not compress under stress making for the perfect weather and bug proof system.

It is provided in 12-foot lengths with pre-punched holes for quicker installation and lower labor costs. The fastening holes are slotted to allow for proper thermal movement of the materials and ensure correct fastener placement and spacing.

Choose among a wide range of standard colors and finishes that meet your job requirements. A 30-year Kynar 500 finish warranty is included on coil-coated standard colors. Custom post-coated Kynar 500 colors are available with an included 10-year Kynar 500 finish warranty or a 20-year Kynar 500 finish warranty is available upon request.

Free Catalog about Natural Ventilation Products

The Bilco Co., a manufacturer of specialty access products, has released its new 2014 Colt Natural Ventilation Products Catalog, detailing Colt’s line of natural ventilation and smoke and fire control products for the commercial markets. The catalog is available free of charge by calling (800) 366-6530, emailing commercial@bilco.com or downloading it.

Bilco partnered with Colt, a United Kingdom-based manufacturer of smoke and natural ventilation products, earlier this year and now serves as the company’s distributor of natural ventilation and smoke control products in North America. The Natural Ventilation Products Catalog features a user-friendly layout, complete with information on the benefits of and the products and options available.

Natural ventilation is becoming an increasingly important design strategy for commercial buildings, particularly in GREEN building design. With careful design, buildings can be cheaper to maintain and operate and the addition of fresh air and natural daylight creates a more pleasant and productive working environment for building occupants. Colt’s products provide an innovative and attractive solution for design professionals and building owners.

CSI Specifications Available for Colt Natural Ventilation Products

New Construction Specifications Institute (CSI) three-part specifications have been developed for Colt natural ventilation products and are currently available online, making it much easier for building design professionals to specify these new products.

CSI is an organization that keeps and changes the standardization of construction language as it pertains to building specifications. CSI provides structured guidelines for specification writing and its MasterFormat serves as the organizational structure for building products in the construction to help architects, engineers, owners, contractors, and manufacturers classify how products are typically used.

CSI 3-Part Specifications are available for Colt natural ventilation products and can be found and downloaded from the Download Center on the Bilco/Colt website.

Ridge Vent Provides Continuous Airflow

Benjamin Obdyke Inc.'s Shark Vent XLP

Benjamin Obdyke Inc.’s Shark Vent XLP

Benjamin Obdyke Inc. has introduced its Shark Vent XLP, an externally baffled shingle-over-roof ridge vent available in 25-foot rolls. Shark Vent effectively extracts heat and moisture from residential attics by providing continuous airflow along the attic ridge, the hottest part of the attic. Its sine-wave-shaped internal and external baffles with 1/8-inchwide vent holes protect attics from rain, snow and insect infiltration. For extreme weather areas, Shark Vent also comes in a filtered option (Xtra).

Add a Glazed Natural Ventilator to the Roof

Colt Group</a>'s Firelight glazed natural ventilator

Colt Group’s Firelight glazed natural ventilator

Colt Group‘s Firelight glazed natural ventilator installs easily in a glass atrium or directly onto the roof of a building. This dual-purpose product provides buildings with day-to-day ventilation and smoke control to aid building evacuation in the event of a fire. Firelight is available in single- or double-leaf design and with control options for automated climate control in a building. This innovative product is now available from The Bilco Company in all North American markets.

Naturally ventilated buildings are generally less expensive to construct and maintain than those that are mechanically ventilated alone. They offer a lower environmental impact through reduced energy demand, which results in lower emissions of carbon dioxide and other combustion products. Further, the addition of fresh air and natural daylight creates a more pleasant, productive, and healthy working environment for building occupants.

Firelight glazed natural ventilators are designed for high aerodynamic, acoustic and thermal performance. The product provides ventilation for most kinds of industrial and commercial buildings and is particularly suited for installation into atriums and glazing systems.

The Firelight is available in several standard designs, each offering a unique appearance and performance to meet the design requirements of any building. Models are available in single or double-leaf construction that can be specified with a powder coat finish to complement or blend into any roof exterior. The product features a thermally broken design to minimize heat loss for reduced carbon emissions into the environment and maximum energy efficiency.

In addition to the standard manual operation, the Firelight can be specified for electric or pneumatic operation and set to open and close as required for proper mixed mode ventilation. With a small initial investment, these systems can provide a highly energy-efficient solution to maintain a good internal climate, low humidity levels and extremely low running and maintenance costs. In addition to climate control, the Firelight control options allow the product to be used as a smoke control system in an emergency situation. These systems save lives by providing smoke-free escape and access routes for building occupants and improving visibility to aid firefighting efforts. They also protect building contents from smoke damage and reduce the overall risk of damage to the building.

Firelight glazed natural ventilators are custom-fabricated to meet virtually any size or building ventilation requirements. Products feature aluminum construction and are available with a number of cover and finish options.

Gibraltar Industries Acquires U.S. Sunlight Corp.

Gibraltar Industries, a manufacturer and distributor of products for building and industrial markets, has acquired U.S. Sunlight Corp., a supplier of solar-powered ventilation products. The acquisition complements Gibraltar’s Air Vent Inc. product offering and customer base in the residential new construction and home-remodeling markets. The addition also brings innovative, energy-saving solar technology.

“We are excited about the addition of U.S. Sunlight to our family of businesses,” says Chuck Jerasa, president of Gibraltar’s Storage and Ventilation business unit. “U.S. Sunlight brings a robust pipeline of cutting edge solar-powered ventilation, lighting and air quality products which will enhance our Air Vent product line and bring immediate value to our customers.”

“Adding this solar ventilation product line will strengthen our position within the growing energy conservation segment of the building materials market space,” adds Gibraltar Chairman and CEO Brian Lipke. “It provides us with access to innovative technology for future product designs and opportunities to grow the business through marketing of additional products to current and prospective Gibraltar customers.”

To ensure a smooth transition and the same outstanding service, the existing management team of U.S. Sunlight will be staying on with the company post acquisition.

New Roofing Ventilation Products

CertainTeed Intake Vent

CertainTeed Intake Vent

Strengthening its position as a one-stop-shop for complete roof solutions, CertainTeed announces the introduction of seven new roofing ventilation products. Part of the CertainTeed Integrity Roof System, the new product line includes CertainTeed Ridge Vent, CertainTeed Rolled Ridge Vent and CertainTeed Intake Vent.

CertainTeed Ridge Vent is available in 7, 9 and 12 inches with filtered and unfiltered options. Each ridge vent is made of high quality co-polymer to remain sturdy, nailable and flexible. Reinforced ribs provide greater stability and rigidity, imprinted slot guides ensure proper slot width, and nail holes and nail lines enable easy, mistake-free installation. The product line also includes a Class A fire-rated vent.

CertainTeed Rolled Ridge Vent, also available in filtered and unfiltered, is designed for use in roof pitches from 3/12 to 12/12. The product features a unique, virtually invisible profile that installs fast.

CertainTeed Intake Vent is easily installed on a shingled roof with or without overhangs, and can be used to supplement existing soffit or undereave vents. Internal baffles, drainage system and weather filter provide three levels of weather protection. The intake vent allows air to flow into the attic and helps prevent heat build-up and ice dams.

The new ventilation products feature proven, effective technology for shingle roofs in all climates and come with a lifetime limited warranty and five-year SureStart Protection.

The products are designed with an external baffle to deflect wind and weather over the vent, creating low pressure above the vent to pull air out of the attic. Each vent comes in a black finish to blend with a variety of shingle colors and create a clean, uncluttered roofline. All provide excellent weather protection and prevent premature deterioration of roofing materials by continuously moving air year-round to improve interior comfort.