Monthly Archives: February 2017

Sealing Snow Guards And Winter Ice Expansion

1As we near the end of winter, it is not too late to start thinking about snow guards. Actually, this is the perfect time to start planning for installation in the Spring. This is especially true for our customers who are choosing to install their guards with our Surebond SB-190 adhesive. This installation method requires approximately 28 days at 50 degrees (Fahrenheit) or above to reach a full cure.  Whether installing snow guards with adhesive or mechanically with screws and sealant, there is one major rule that must be followed. The sealant or adhesive MUST cover the entire base of the guard to create a full seal. Cutting corners during this step can lead to costly repairs and major headaches.

Winter weather brings many forms of precipitation, each with its own set of issues.  These can lead to guard failures or leaks, if a proper seal is not achieved. Most liquids have a simple behavior when they are cooled (at a fixed pressure): they shrink. Water is one of the few exceptions to this behavior. When liquid water is cooled, it contracts like one would expect until a temperature of approximately 4 degrees Celsius (39.2 degrees Fahrenheit) is reached. After that, it expands slightly until it reaches the freezing point, and then when it freezes it expands by approximately 9%. The constant cycle of melting and re-freezing on metal roofs can cause water to seep into the cracks and air-pockets between a snow guard and your roof. The pressure of rushing rain-water can also allow liquid to force itself between the guard and your roof.  The expansion of this frozen water can pry the guard away from the roof, potentially causing guard disengagement from the roof and/or leaks where the screw holes are no longer protected. While this will rarely cause damage to the guard itself, corrosion to the panel and/or warping and rotting of the roof’s wooden structure can become costly repairs once warmer weather reveals winter’s damage.

2When installing snow guards, it is vital to their installation for a proper seal to be created over the entire base by applying a liberal coating or either sealant or adhesive. Once the base is covered, press the guard against your roof with enough pressure for any air-pockets or gaps to be completely filled. This should also result in oozing around the outside edge. A gloved finger can be ran around the outside perimeter of the guard to remove excess and to also complete the guard’s seal. A few extra seconds can make a world of difference when it comes to your snow guard system’s performance. Don’t allow expanding ice to remove your hard work!

Share Button