KnuckleHeads and Hurricanes

Recently Green Link principals, Phil Georgeau, Founder, and Lisa Mulder, Technical Director traveled to San Juan, Puerto Rico to survey the destruction caused by Hurricane Maria, and to study how the use of the KnuckleHead support system could provide more stable rooftop installations in the face of future hurricanes.

Hurricane Maria, which struck in September, 2017, was a cat 5 which brought 150-180 mph winds for 12 hours on the eastern side of Puerto Rico.  Georgeau and Mulder visited the island in April of 2019—more than a year and a half later, but reported that the damage was evident.  Much of the destruction had been bulldozed away and many buildings were completely lost—especially wood construction in the hills surrounding the city.  Telephone poles were knocked down, and while new lines had been installed, the old stuff was still laying on its side.

An unattached Mini Split toppled by high winds.

Concrete buildings survived for the most part, but many roofs were empty of pipes and equipment.  Much of the roofing featured concrete with torched down mod bit roof membrane.  These roofs survived for the most part but unattached roof mounted equipment and pipelines were swept away.  The equipment that still remained lay on its side.  Clearly, loose laid pipes and equipment will not survive high winds.  Because San Juan has a population of 350,000 people in limited space, everything has to go on the roof.

A typical commercial roof in Puerto Rico. All equipment is placed on the roof because of narrow streets.

Georgeau and Mulder observed that rooftop installations that survived the hurricane were attached, and this makes the case for the KnuckleHead support system.  Unlike most other pipe and equipment supports, KnuckleHeads can be attached.  The base design allows for mechanical fasteners to be pushed through two holes in the center of the base.  In addition, the base is designed to be attached with adhesive, specifically Green Link Adhesive/Sealant, which bonds to roof membranes as well as the molded nylon base of the KnuckleHead.  Using both mechanical fasteners combined with adhesive will provide a firm and stable installation that will greatly increase the probability of rooftop installations to survive high winds.

Attached equipment survived the hurricane. The reddish color on the air handler is rust from exposure to rain and ocean salt water.

Green Link engineers are currently studying the performance of attached KnuckleHead supports under violent wind conditions.