At S-5!, we don’t recommend installing adhesive-mounted snow guards on metal roofs. From both an economic and design perspective, glued on plastic snow guards typically have low holding strength and are unable to handle harsh weather-related elements. The bond weakens over time and when it fails, the guard can rip away paint and protective roof coatings, potentially leading to corrosion.

This is part one of a two-part series on qualifying snow retention systems.

In places where it frequently snows a lot and even in places where it doesn’t, metal is a favored material in protecting a house or other structure. On the surface, snow might appear to be rather innocuous, as it gently falls from the sky like the ending scene in the movie, White Christmas. But what the movie doesn’t show, is all through the night and much of the morning (if not longer) the light fluffy stuff piles deeper and deeper on top of the roof, incrementally increasing its own weight. Then, when the sun comes out, an avalanche of snow tumbles down onto unsuspecting persons, vehicles and landscapes below. 

When a snow avalanche falls off of a rooftop, it can damage anything in its path! This sudden release of snow can be dramatic—dumping tons of snow in mere seconds. Falling snow forms a temperature-sensitive bond to the surface of a metal roof. Then, when that roof is warmed, whether from the sun or from building heat loss, the bond between the snow bank and roof is broken and a thin film of melt water serves to lubricate the slide.