Markham conditions that change how chimney crown replacement is done
Most Markham homeowners book chimney crown replacement for one reason and discover a second problem on the same visit.
Post-war subdivisions across York share the same construction generation, so when one street starts showing the same defect, the neighbours usually follow within a couple of seasons.
Many Markham properties were re-roofed at least once without the flashing being re-detailed, leaving a cosmetic seal doing structural work.
Across German Mills, Bayview Glen, Greensborough, Aileen-Willowbrook and Old Markham Village, 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 crown replacement 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.