Rooftop Equipment Mounting and Penetrations for Low-slope Standing-seam Metal Roofs

Standing-seam metal roofing offers a durable, sustainable alternative to other roof types and can provide maintenance-free service for five to 10 decades. Sadly, this exceptional lifespan often is sabotaged with the mounting of essential rooftop equipment and ancillary mechanicals.

Metal roofing can make use of special seam-clamping hardware that grips the standing seam without puncturing the membrane. Seam clamps have made metal roofing a preferred roof type for mounting photovoltaic solar arrays. PHOTO: Metal Roof Advisory Group Ltd.

Metal roofing can make use of special seam-clamping hardware that grips the standing seam without puncturing the membrane. Seam clamps have made metal roofing a preferred roof type for mounting photovoltaic solar arrays.

Regardless of the roof type involved, consultants generally agree that the best way to prevent roof-related problems is to clear the rooftop of everything possible and just let it function as a roof—not a mechanical equipment platform. However, such a perfect roof continues to elude us, as it becomes necessary or convenient to mount HVAC equipment, screens to hide it, piping to fuel it, scuttles to access it and walkways to service it. The list of rooftop mountings also may include plumbing vents, satellite dishes, lightning protection, snow retention systems, solar collectors, advertising signage and fall-protection systems to maintain all the foregoing. To help achieve relatively trouble-free roofs, this segment provides some basic understanding of the dos and don’ts in situations where rooftop equipment mounting is requisite.

Penetration-free Attachment

A good “first rule” about any rooftop mounting is to avoid penetrating the membrane whenever possible. While this may seem obvious, the tenet is often violated with standing-seam metal. The norm for attaching things seems to involve anchoring the item to the structure through the roof. When this happens, it not only threatens weather integrity, but can also violate the membrane’s thermal-cycling behavior by inadvertently pinning the panel to the structure. Such a point of attachment will fatigue and fail from forces of thermal expansion within a short time. Fortunately, scores of items and equipment can be securely mounted to metal rooftops without any penetration whatsoever, actually making metal roofing more user-friendly than other roof types.

In terms of mounting ancillaries, metal roofing can use special seam-clamping hardware that grips the standing seam without puncturing the membrane. Unlike many other types of roofing, metal is a rigid, high-tensile material. The seam area creates a beam-like structure that can provide convenient anchorage for walkways, solar arrays, condensing units and gas piping without harming the roof’s weathering characteristics. Mechanicals can be safely and cost-effectively secured to these seam clamps, leaving the roof membrane penetration free. Seam clamps can provide holding strength of up to several thousand pounds on some profiles and gauges, last the life of the roof and preserve thermal-cycling characteristics. Using seam clamps when possible for ancillary mounting will eliminate unwanted holes and other potential problems.

Seam clamps allow even cumbersome ancillary items to be attached to metal roofs without penetrating the rooftop. PHOTO: Metal Roof Advisory Group Ltd.

Seam clamps allow even cumbersome ancillary items to be attached to metal roofs without penetrating the rooftop.

Clamps should be made only of noncorrosive metals—typically, aluminum with stainless-steel mounting hardware. These metals are compatible with virtually anything found on a metal roof, except copper (with which there are dissimilar metallurgy issues). Dissimilar metals in electrolytic contact will induce galvanic corrosion of the less noble metal. In cases involving copper roofing, brass clamps should be used with stainless-steel hardware.

Seam clamps generally integrate with the profile and seam folding, and in some way “pinch” the seam material to anchor them in place. Preferred methods of doing this involve setscrews tightened against the seam causing a detent in the seam material that in turn creates a mechanical interlock of the setscrew, seam and clamp, providing the greatest holding strength and durability. Setscrews should have round, polished points to prevent galling metallic coatings, which can lead to corrosion. In like fashion, and regardless of the method of engagement, any clamp device should avoid any sharp points or nodes that could potentially pierce or gall metallic coatings of steel or cause fatigue and fracture points of other metals.

It also is important to remember that any loads introduced into the clamp will be transferred to the panels and their anchorage to the structure. Consequently, anchorage must be capable of withstanding the added load. The best practice is to utilize clamps that have been appropriately tested for material and seam-specific holding strength; be sure in-service load does not exceed that of the published holding strength, including factors of safety. The roof manufacturer should also be consulted with respect to approval of devices used.

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South Carolina’s Workers’ Compensation Laws Have Changed to Benefit the Injured and their Employers

Ensuring compliance with workers’ compensation laws is consistently a concern among many states because of the impact noncompliance can have on injured employees and employers who follow the law. Noncompliance with workers’ compensation laws negatively affects those injured on the job, as well as law-abiding employers. Fortunately, the workers’ compensation laws of South Carolina are implemented relatively efficiently and result in more resolved cases for injured workers than many other states. Some recent changes in the state’s laws are designed to make the process more efficient.

Workers’ compensation insurance provides medical benefits and wage reimbursement for employees who become injured while on the job. The South Carolina Workers’ Compensation Act provides that injured employees are entitled to recover necessary medical treatment, loss of wages during a period of disability, and compensation for permanent disability or disfigurement. There are three types of work-related injuries that can qualify for workers’ compensation payments: physical injuries, mental injuries accompanied by physical injuries and mental injuries with no physical injuries.

In South Carolina, employees may collect workers’ compensation for all wages and benefits, including those from other employers. This gives South Carolina employees an advantage over neighboring North Carolina employees who may only collect workers’ compensation for wages earned from the specific job on which the injury occurred.

Who Is An Employee?

The South Carolina Workers’ Compensation Act defines “employee” as “every person engaged in an employment under any appointment, contract of hire or apprenticeship, express or implied, oral or written … but excludes a person whose employment is both casual and not in the course of the trade, business, profession, or occupation of his employer … .”

Every South Carolina employer and employee is presumed to be covered by the act. Employers covered by the act are required to maintain insurance to cover compensation or provide the South Carolina Workers’ Compensation Commission with proof they have the ability to pay the compensation for an injured employee.

There are a few exceptions to the workers’ compensation laws, including businesses employing fewer than four employees or having a total annual payroll of less than three thousand dollars in the previous calendar year, regardless of the number of employees. Employers who qualify for exemption may elect to come under the act and may subsequently withdraw with written notice to the Workers’ Compensation Commission.

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Whether Hands-free, Handheld, Texting or Talking, Distracted Driving Is Deadly

The Washington, D.C.-based National Transportation Safety Board (NTSB), an independent safety agency, recently recommended a total ban of all mobile-device use while driving. According to Deborah Hersman, the chairman of the NTSB, distraction-related crashes killed 3,092 people in 2010, “the equivalent of a regional jet crash every week.”

Every year, drivers–distracted by the use of mobile devices–cause 636,000 crashes, 342,000 injuries and 2,600 deaths. The financial toll is staggering: $43 billion per annum. While some politicians argue about the science behind distracted driving, experts agree: mobile-device use impairs driving ability. According to a study at Carnegie Mellon University, Pittsburgh, talking on a mobile device reduces the amount of brain activity related to driving by 37 percent. Further, recent studies show hands-free mobile devices are no safer to use while driving than handheld mobile devices. Distracted drivers have slower reaction times, and the odds of a crash are four times more likely when a driver uses a mobile device. Critically, many scientists believe these distractions make drivers as collision- prone as having a blood alcohol level of 0.08 percent, the legal limit.

Legal Landscape

In the last 10 years, courts have seen an “explosion” of distracted-driving cases.

In the last 10 years, courts have seen an “explosion” of distracted-driving cases.

In the last 10 years, courts have seen an “explosion” of distracted-driving cases. In the last five years, juries–emboldened by a “profits over safety” trial theme–have rendered numerous multimillion dollar verdicts, as evidenced by the sample verdicts in Figure 1, left.

The claims in these cases are easy to allege but difficult to disprove. This is because the precise time of the accident often is not known and the telematics data and mobile-device records—once obtained—may show or suggest that the employee was talking on his mobile device, texting and/or emailing in close proximity to the time of the accident. Even if there was no actual distraction, a clever lawyer will argue there is “circumstantial evidence” of driver distraction.

The typical distracted-driving case involves multiple types of claims, including driver negligence, vicarious liability, direct negligence and punitive damages.

Driver Negligence

In states that ban texting and/or the use of handheld cell phones while driving, an employee who is involved in an accident while violating these laws will be negligent per se. Under this doctrine, the mere act of using a mobile device while driving automatically makes the driver negligent.

For states that do not have texting and/or cell-phone bans, courts look at the reasonableness of the driver’s accident-causing behavior. In evaluating behavior, courts will consider state laws, federal regulations, voluntary standards, recognized best practices and common sense. For example, in Scott v. Matlack Inc., the court explained, “it is permissible for a trial court to admit [OSHA] regulations as evidence of the standard of care in the industry in a negligence action.” Likewise, in Peal by Peal v. Smith, the court observed, “the breach of a voluntarily adopted safety rule is some evidence of a defendant’s negligence.”

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Roof Maintenance, Sustainability and RoofPoint Life-cycle Management

The roofing industry knows good design, quality materials and proper installation are the key tenets to achieving a leak-free, long-term roofing system. Roof system maintenance is an equal part of the equation and should not be overlooked, even though there is a tendency for “out of sight, out of mind” by many building owners.

A technician from Sheridan, Ark.-based RoofConnect walks a roof and documents it as part of an annual maintenance survey. RoofConnect, which has locations around the country, including Monroe, N.C., has made maintenance contracts a major part of its business.

A technician from Sheridan, Ark.-based RoofConnect
walks a roof and documents it as part of an annual maintenance survey. RoofConnect, which has locations around the country, including Monroe, N.C., has made maintenance contracts a major part of its business.

Roof maintenance is not only important to long-term service life, it is a key factor for the overall sustainability of roof systems. RoofPoint, the Washington, D.C.-based Center for Environmental Innovation in Roofing’s Guide for Environmentally Innovative Nonresidential Roofing, emphasizes durability and life-cycle management for sustainable, environmentally friendly roof systems. Of the 23 credits within RoofPoint, nine are in the Durability/Life Cycle Management (D/LCM) section. It’s clear the roofing industry recognizes the importance of longevity when it comes to environmentally friendly roof systems.

Looking deeper into RoofPoint, one of the nine credits in the D/LCM section is titled “Roof Maintenance Program”. Establishing and maintaining a partnership with the building owner is a win-win for the roofing contractor and the building owner. Performing inspections
and maintenance provides the owner with an ongoing information resource, ultimately allowing better management of capital and the roof asset by extending the life of the roof system.

From a sustainability perspective, a longer lasting roof—extended by regular roof system maintenance—means roof replacement is appropriately postponed and with that comes a reduction in material and energy use, as well as reduced expense and waste. Roof system maintenance is a win for the owner, the environment and the roofing contractor.

PHOTOS: RoofConnect