Two houses on the same Toronto street, built the same year, can need completely different gutter install guide work — and usually do.
Range hoods and basement bathroom fans routinely out-pull an older flue, so the house depressurises and the flue reverses — a Toronto problem that looks like a chimney fault but starts elsewhere in the building.
Older Toronto stock was built when soft lime mortar and clay liners were the standard; modern high-efficiency appliances vent very differently, and the mismatch causes condensation the original builder never planned for.
Across Forest Hill, Don Mills, Leaside, Greektown and Davisville, 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.
If you live anywhere near the CN Tower, the practical takeaway is that a gutter install guide 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.