Why Good Roofs Go Bad
Could it be that the Pareto principle applies to commercial roofing? It’s not uncommon to find that approximately 20% of the roof — meaning the penetrations — can cause roughly 80% of the problematic issues.
Penetrations are among many potential failure points in a roof system. It is prudent to be particularly aware of potential failure points when specifying, installing and maintaining a roof, because many of them can be managed proactively — or avoided entirely — due to new and emerging technology.
Common potential failure points include:
Penetrations in this case are any instances where holes are put in the roof. Typically on a commercial roof that includes HVAC components, vent pipes, drains, skylights, roof hatches, antennas, etc. It stands to reason that holes in the roof — when not properly sealed — are the most vulnerable spots for water to find its way in. While penetrations are unavoidable, how they’re sealed and maintained can differ. Most roofers will use metal flashing around penetrations as a way of keeping water out. But how effective are these solutions over time? The act of bending, heating and manipulating metal to conform to penetrations by definition breaks it down and weakens the material, as well as can pose risk of corrosion.
Not properly installed and maintained, metal flashing can be a common originating point of roof failures. Liquid-applied waterproofing materials, conversely, conforms to the shape of the penetration upon application, and can be layered to produce even greater water resistance.