Do skylights leak more in Vancouver's wet climate?

Yes, skylights do have a higher risk of leaking in Vancouver's climate — but a properly installed, quality skylight should not leak. The combination of our 1,200mm+ annual rainfall, frequent freeze-thaw cycles, and moss/debris accumulation does put more stress on skylight installations than in drier climates, making quality installation and regular maintenance especially important here.

The most common cause of skylight leaks in the Lower Mainland isn't the skylight itself — it's the flashing. Flashing is the metal and membrane system that seals the skylight to your roof, and it's where most failures happen. In Vancouver's wet climate, any gap, crack, or improper overlap in the flashing becomes a water entry point almost immediately. Poorly installed step flashing, inadequate underlayment, or flashing that wasn't integrated with a proper rain screen assembly are the usual culprits. A quality skylight from a reputable manufacturer (Velux, Fakro, and Sun Tunnel are common in the Lower Mainland) with properly installed self-flashing or curb-mounted flashing will perform well even in our rainy seasons.

Condensation is often mistaken for a leak. Vancouver's humid interior air hitting a cold skylight surface creates condensation that drips down — homeowners frequently assume they have a leak when the issue is actually moisture management. Proper ventilation and double or triple-glazed units with low-e coatings significantly reduce this problem. If you're seeing water only on cold mornings and it seems to come from the glass surface rather than the frame or ceiling, condensation is likely the culprit.

Roof pitch matters a lot here. Skylights on low-slope roofs (under 3:12 pitch) accumulate standing water, debris, and moss far more than those on steeper pitches. In Vancouver, where moss grows aggressively, debris can dam up around a skylight curb and force water underneath flashing that would otherwise drain freely. Zinc or copper strips installed upslope of the skylight can slow moss growth, and annual cleaning is worth the effort.

From a permit and code standpoint, skylight installations in the City of Vancouver and most Metro municipalities require a building permit if the skylight is new — not a replacement in kind. The BC Building Code (BCBC 2024) governs glazing requirements, minimum slope, and fall protection considerations for roof access. Replacement skylights in the same opening typically don't require a permit, but adding a new opening does.

Typical costs in Metro Vancouver run $800–$1,500 for a standard fixed skylight replacement (materials and labour), $1,500–$3,500 for a new installation with flashing and interior finishing, and $3,000–$6,000+ for venting skylights or larger units. If rot repair or sheathing replacement is needed around an old leaking unit, budget an additional $500–$2,000.

For professional installation, look for a roofing contractor with specific skylight experience — not all roofers install them regularly, and flashing detail is a skill. A licensed roofing contractor with WorkSafeBC coverage and $2M liability insurance is the minimum you should accept. Browse qualified roofers in our Vancouver Construction Network directory to find local professionals familiar with Lower Mainland conditions.

Your next step: If you have an existing skylight that's leaking, get a roofer up there before the fall rains hit in October. Have them inspect the flashing, curb, and surrounding shingles or membrane. Catching a minor flashing issue in September is a $300–$600 repair — ignoring it through a Vancouver winter can mean $5,000+ in rot, drywall, and insulation damage.

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