Mould needs moisture to grow, so mould control is really moisture control. In BC's damp climate, managing humidity and leaks keeps mould from taking hold in the first place.
Control humidity
Keep indoor humidity in a healthy range — run bathroom and kitchen exhaust fans, use a dehumidifier in damp basements, and avoid drying laundry indoors without ventilation. Condensation on windows is a sign humidity is too high.
Fix leaks fast
Roof, plumbing, and foundation leaks feed hidden mould inside walls and ceilings. Address water intrusion promptly and dry wet materials within a day or two — mould can start growing within 24 to 48 hours of a soaking.
Handling mould
Small areas of surface mould on hard surfaces can be cleaned, but large infestations, mould in porous materials, or mould from ongoing leaks need professional remediation and, crucially, fixing the moisture source so it doesn't return.