Why roof moss & algae treatment works differently in St. Catharines
What makes roof moss & algae treatment in St. Catharines unusual is not the technique, it is the age spread of the housing: a single route can cover 1910 brick and 2019 factory-built venting.
Air-sealing and window upgrades have made St. Catharines homes far tighter than they were designed to be, and a tight house starves a natural-draft appliance of the make-up air it needs.
Range hoods and basement bathroom fans routinely out-pull an older flue, so the house depressurises and the flue reverses — a St. Catharines problem that looks like a chimney fault but starts elsewhere in the building.
Across Vansickle, Western Hill, Lakeshore, Queenston and Glendale, 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 Welland Canal, the practical takeaway is that a roof moss & algae treatment 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.