The local factors behind chimney relining (stainless) in Markham
The difference between a $200 service call and a $6,000 rebuild in Markham is usually about eighteen months of ignoring a small symptom.
Wind loading off Lake Ontario pushes driving rain against the south and west faces of a house, which is why water entry so often shows up on one side of a Markham home and nowhere else.
Snow load and ice damming stress the roof-to-wall junction each winter; by spring the sealant that was doing the work has usually torn.
Across Victoria Square, Buttonville, Thornhill Markham, Cathedraltown and Raymerville, 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 Main Street Unionville, the practical takeaway is that a chimney relining (stainless) 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.

