While safely on the ground toss a Roofmelt tablet onto the roof. Contains 95 Percent of Calcium Chloride and works down to -20 Degrees F. Comes in a 14 LB Pail and is an estimated 60 Pucks per container. Apply 1 tablet on every SQFT Of Problem Area. FAST ACTING: Begins working within 1 Hour of application. | Roofmelt tablet then melts its way down and settles on the roofs surface | Roofmelt begins to work when it comes into contact with snow and ice, the Roofmelt and water mixture begin to melt away the existing ice dam. | Water drains from the roof to the ground, the ice dam and snow are safely eliminated. | PURPOSE: ROOFMELT IS DESIGNED TO MELT THROUGH THE ICE CREATING RELIEF POINTS FOR DRAINAGE. THIS ALLOWS TRAPPED WATER TO FLOW OFF THE ROOF AND NOT CAUSE HARM TO ROOFING MATERIALS.