The honest summary of ice dam risk in Orangeville is that the work is simple and the diagnosis is not.
The swing between a January cold snap and a February thaw can move a masonry assembly enough to open joints that looked sound in the fall.
Infill and renovation work in Orangeville frequently reroutes venting without re-sizing it, and undersized or over-long runs are the single most common cause of poor draft we see.
Across Purple Hill, Credit Meadows, Downtown Orangeville, Century and Fendley, the housing stock changes street by street, and the correct method changes with it. A century home with a soft-brick stack does not get the same treatment as a 2010 build with a factory-built vent — using one method on both is how systems get damaged.
the practical takeaway is that a ice dam risk visit should start with an assessment, not a tool. Any crew that begins work before telling you what they found is guessing on your behalf.