An ice dam forms when snow melts on a warm roof and refreezes at the cold edge, trapping water behind it. The trapped water finds gaps under shingles and then drips into insulation, ceilings and walls where nobody sees it.
Snow loads in Massachusetts
State resilience guidance lists major snowstorms in 2013, 2015 and 2018 that dropped about 2 feet of snow in under 24 hours. That is regional data, not Sterling roof records, but it shows why heavy roof snow is a standing winter concern across the state.
- Photograph ceiling stains and drips with the date.
- Place buckets and plastic, and move furniture aside.
- Keep attic access clear for the crew's meters.
- Leave snow removal from steep roofs to a roofer.



