Roofing in Nanoose Bay

Table C-2 lists Nanaimo at 1,000 mm of annual rainfall with a ground snow load of 2.1 kPa, and Parksville at 1,200 mm with 2.0 kPa. Nanoose Bay sits between them and appears in neither row.

The gap is narrower than the one facing the inland communities, but it runs the other way on snow load, so the conservative choice is not the same row on both counts. Where a roof is being specified rather than simply replaced like for like, that is worth resolving deliberately instead of defaulting to whichever town is nearer on a map.

Both listed locations share a one-day design rain of 91 mm and a 1-in-50 hourly wind pressure of 0.50 kPa, so those two figures are settled whichever row gets picked.

The Regional District of Nanaimo's own community plan for the area describes rocky cliffs and rocky beaches around Nanoose Hill, interspersed with little gravel pocket beaches, and Nanoose Harbour as a sheltered estuary and associated tidal flat. Those are two different weather environments a few kilometres apart.

A roof on an exposed bluff takes wind and driving rain on one elevation continuously through the winter. A roof on the harbour side of the same community sits in shelter, and the limiting factor there is more likely to be shade and moss than wind uplift.

No tabulated design value captures that difference. It gets captured by walking the property and looking at which elevation has taken the wear.

Nanoose Bay is unincorporated, so the Regional District of Nanaimo governs building permits. Roofing repairs or replacements sit on the RDN's list of work that does not require one, provided no structural changes are made.

The plan area covers roughly 7,382 hectares over three geological groups — the Upper Cretaceous Nanaimo Group of sandstone, conglomerate, shale and coal, the Karmutsen Volcanics, and the Buttle Lake Group — and around 13,000 years ago the whole area lay under more than a kilometre of ice.

For roofing that shows up indirectly, in access and staging. A house set on a rock bench with a steep drive and no flat ground beside the eave is a different day's work from a level lot, and that belongs in the quote rather than being discovered on the morning.