The local factors behind ice dam prevention in Port Hope
Ask any technician who works Port Hope routes and they will tell you the same thing: the callbacks cluster in a handful of predictable places.
Range hoods and basement bathroom fans routinely out-pull an older flue, so the house depressurises and the flue reverses — a Port Hope problem that looks like a chimney fault but starts elsewhere in the building.
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.
Across Welcome, Elizabethville, Ganaraska, Penryn and Old Port Hope, 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 prevention 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.