By: Adam McManus, May 27, 2020
There are weather events that often prove to be anomalies and are known to be particularly severe; these events may pass through in a few days or weeks. In October 2012, Hurricane Sandy caused floods, power outages, fuel shortages and many other inconveniences to everyday life, particularly in the NYC metro area. Annually, there are Nor’Easters, ice storms, snow storms, heavy sustained rains, and significant temperature swings that all are part and parcel for seasonal and unseasonal weather patterns. On the extreme side of those weather events, the building enclosure of any structure is the front line and primary protection. It is particularly helpful to be proactive about planning for maintenance and repairs that could prevent significant damage during future extreme weather events.
Nor’Easters are wind driven rain or snow events that primarily impact buildings along the north and east facing elevations. High winds can blow rainwater/snow sideways and sometimes a vortex with multidirectional gusts. This phenomenon can challenge the watertight integrity of any façade system, including fenestrations, known as an openings in the wall systems. These openings are typically protected with sealant joints. It is quite common for nor’Easters to cause the saturation of the building elements such as brick, mortar and other water permeable features. If the water saturation is followed by freezing temperatures, the impact is compounded since freeze-thaw cycles can be quite damaging to masonry building elements.
Ice storms may be caused by rain that falls into a sub-freezing temperature layer before making contact with the ground. Ice may form on a/c units and other building appurtenances; during a rising temperatures, significant ice build-up may break off with the potential to impale building elements including roof system membranes, skylights and other vulnerable areas on building roof set backs.
Wet and dense snow fall, especially from a heavy accumulation can add significant load to appurtenances, balconies and light capacity roof systems. Appurtenances that are most impacted are canopies attached to buildings and similar attachments. A freeze thaw period with dense snow is likely to form ice within the snow accumulation.
Heavy sustained rains can overwhelm roof and terrace drains, causing a bathtub effect. On occasion, a heavy rain storm is capable of overwhelming wall membrane flashing and vulnerable seams in the roof membrane systems. When that occurs, there can be delayed interior leaks.
Metals and alloys expand and contract and when jointed with dissimilar materials, those joints are placed under stress by extreme temperatures. The most vulnerable points of a building are those joints between dissimilar materials. These joints are typically bridged with sealants, including bond breaker tape, closed and open cell foam as backer material. Closed cell foam has very minimal expansion and contraction while a quality open cell foam can typically be expanded and contracted up to 100% of its relaxed state.
During and after significant weather events, it is common to have reported leaks. It is also common that these leaks may be difficult to recreate if the existing systems are typically watertight. The proactive way to avoid unnecessary and preventable failures at the facades, windows and roof systems, is to have comprehensive building envelope surveys performed. Surveys can provide the basis for a detailed maintenance and repair or restoration program to address exteriors that are vulnerable to failure.
Recently, we have been in the throes of a global pandemic, that has not occurred on this scale since 1920. It is May 2020 and the interruption is not over yet; the take-aways and lessons learned seem to be inexhaustible. Construction sites are mostly shut down in the New York City area, with the exception of those that are classified by the Department of Buildings as essential construction. Since the weather patterns have been mild in nature, the direct impact from the shut-down has been largely an economic hit. Construction is stopped and the craftsmen, architects/engineers, property managers, and owners are all awaiting a release to ramp up again. Resuming planned restoration projects can be particularly important since these are repairs that restore the watertight and structural integrity.