Roofing in French Creek

Table C-2 of the BC Building Code lists Parksville and Qualicum Beach, and nothing between them. French Creek sits in that gap, and the two rows do not match: 91 mm against 96 mm for one-day design rain, and a 1-in-50 hourly wind pressure of 0.50 kPa against 0.53 kPa.

The code's own direction for a location that is not listed is to obtain recommended design values from Environment Canada. In practice a designer works from the nearest listed community, and on a shoreline lot the conservative choice is the higher row.

That is not an academic point. The gap between the two rows is close to the margin a rake edge or a ridge closure on an exposed lot will actually test.

French Creek is unincorporated, so the Regional District of Nanaimo building department has jurisdiction rather than a municipal one. The RDN publishes a plain list of work that does not require a building permit, and roofing repairs or replacements appear on it, provided no structural changes are made.

The permit list is where a job crosses back over. Alterations, additions or repairs to an existing building or structure, interior structural renovations, and installing solar panels each require a permit in their own right.

Sheathing replaced like for like is repair. Altered rafters, a new opening or a changed roof line is not, and a solar install planned alongside a re-roof brings the permit question back whichever way the roofing answer goes.

Electoral Area G runs from the waterfront back inland, and the difference across a few hundred metres is larger than the difference between the two code rows. A lot facing open water takes driving rain and wind on one elevation right through the winter, and the leeward slope of the same roof can look a decade younger than the seaward one.

That shows up as a specification decision rather than a price decision. Heavier edge fastening on the exposed face, closures wherever a panel or shingle course terminates, and eave membrane run further up the slope than the code asks for — because here the code asks for none. Article 9.26.5.1 exempts regions with 3,500 or fewer degree-days, and the two listed communities either side of French Creek both sit at 3,200.