RICHARD GALLAGHER, line of business director-property, for Zurich Services Corp.
Keeping water out is the job of the building envelope, which includes the roof, walls, windows, and doors. This is the case for water from wind-driven rain, coastal storm surge, runoff from heavy rain and river flooding. This article provides a checklist for business owners to help them protect their properties in particular from wind-driven rain during a tropical storm.
Risk managers should periodically take time to conduct a visual assessment of their building envelope and promptly correct any weaknesses.
Zurich recommends monthly assessments; however, assessments should also be conducted before and after any high-wind event. When performing a visual building envelope assessment, risk managers should look for the following potential issues:
Secure rooftop equipment
that is either curb-mounted or stand-mounted. Stand-mounted equipment includes air conditioning condensers, large fans and cooling towers. These units should be securely fastened to the stand, and metal straps should be provided for additional securing. (See photo here of air conditioning condensers with straps.)
When stand-mounted equipment is dislodged by wind, it becomes wind-borne debris that can damage the roof cover and other rooftop equipment.
Curb-mounted rooftop equipment includes exhaust fans and air intakes. Curb-mounted equipment should be secured to the curb with corrosion resistant screws at six-inch intervals along each side of the curb. In addition, wire rope should be provided for additional securing for features such as exhaust fan cowlings. (See photos here of secured exhaust fans and goose-neck air intake.)
When curb-mounted equipment is dislodged by wind, it not only becomes wind-borne debris, it also leaves behind large openings for wind-driven rain to enter.
Satellite dishes, as common
as they are on rooftops, typically have limited wind resistance.
They are often secured with concrete blocks as ballast. Rather than attempting to secure satellite dishes, expand your hurricane plan to include stowing satellite dishes, supports and concrete blocks so they cannot become wind-borne debris or cause damage to the building, letting water seep in thru the gaps. (See photos of satellite dishes before and after high winds.)
Inspect perimeter roof flashing. Flashing is often secured using a hidden hook strip. If the flashing is not firmly engaged to the hook strip, it can fail under high winds. Where there are indications that perimeter flashing is not firmly engaged, it should be face-fastened to the building wall using corrosion resistant screws backed by neoprene washers. (See photos of failed and face-fastened flashing.)
When perimeter edge flashing fails, significant water intrusion usually follows.
systems can lead to major roof damage.
These systems consist of air terminals (lightning rods) and ground conductors (wires) that protect the building from lightning strikes. If these systems become loose during high winds, significant rooftop damage can occur.
Often, lightning protection systems are secured with lightweight metal clips. These clips and air terminals are attached to the building with adhesive. These lightweight clips should be replaced with more substantial clamps, and adhesives should be replaced with mechanical fasteners.
(See photo of an air terminal causing roof damage.)
Roof coverings showing signs of damage or wear should be scheduled for immediate repair by a roofing contractor.
Risk managers who work in areas prone to hurricanes should consider keeping a roofing contractor on retainer to help their businesses be first in line for repairs before or after a high-wind event.
Debris on roofs or balconies can obstruct drains and lead to water accumulations. When water is allowed to accumulate, it can back up under roof flashing systems or into balcony doorjambs. In either case, significant water intrusion can occur. This debris can also become wind-borne and damage the roof covering or other building envelope features. So, make it a practice to keep rooftops free of debris as well as idle tools and equipment.
Inspect doors and windows for signs of damage or duress.
Damage may include broken glass or inoperable locks and latches. Duress may include corrosion and wear. Visible deficiencies should be promptly repaired or replaced.
The above checklist offers a starting point to help risk managers and business owners protect their buildings during a hurricane. Because each facility is designed differently and has unique conditions and challenges, it's key to create a visual assessment checklist tailored to the building's specific characteristics. Keep in mind that the overall objective is to find water intrusion deficiencies before the next hurricane does.
IS THERE MORE?
Actually, there is more to consider. The visual building assessment is an essential practice to protect a hurricane-exposed property. However, these assessments alone may not be enough. Buildings must also be designed for the local wind exposures and must be maintained in good repair.
For more thoughts on wind resistance, see the Zurich recommended practice for facilities in hurricane-prone regions, which provides guidance on improving a facility to Zurich Highly Protected Risk Wind standards.
This and other useful information are available at the Zurich Hurricane Information Center and the Zurich HelpPoint Windstorm Web site.
The information in this publication was compiled by Zurich Services Corp. from sources believed to be reliable. We do not guarantee the accuracy of this information or any results and further assume no liability in connection with this publication, including any information, methods or safety suggestions contained herein. Moreover, Zurich Services Corp. reminds you that this publication cannot be assumed to contain every acceptable safety and compliance procedure or that additional procedures might not be appropriate under the circumstances. The subject matter of this publication is not tied to any specific insurance product nor will adopting these procedures insure coverage under any insurance policy. Zurich Services Corp. does not guarantee particular outcomes, and there may be conditions on your premises or within your organization that may not be apparent to us. You are in the best position to understand your business and your organization and to take steps to minimize risk, and we wish to assist you by providing the information and tools to assess your changing risk environment.
July 1, 2010
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