What makes emergency roof tarp in Markham its own problem
There is a rhythm to emergency roof tarp work in Markham: a quiet summer, a frantic October, and a winter of emergencies that were visible in September.
Infill and renovation work in Markham frequently reroutes venting without re-sizing it, and undersized or over-long runs are the single most common cause of poor draft we see.
Range hoods and basement bathroom fans routinely out-pull an older flue, so the house depressurises and the flue reverses — a Markham problem that looks like a chimney fault but starts elsewhere in the building.
Across Grandview, Angus Glen, Bayview Glen, Bayview Fairways and Milliken, 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 emergency roof tarp 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.

