What Wellington weather asks of a skylight
Rain driven by the wind
Wellington Airport records gusts over 63 km/h on 166 days a year. Wind-driven rain can travel up and under a flashing that would stay dry in still weather, so a skylight here needs a flashing kit made for your roofing profile, fitted with the right overlaps.
Hail on the southern side
Kelburn averages 9 hail days a year, and NIWA says hail is more frequent on the southern coast as unstable southerlies rise off the sea. It's worth asking which glazing stands up best to hail if you're in the southern or hill suburbs.
Damp winters and cold glass
Mean 9 am humidity at the airport peaks at 81.1% in June and July. Warm, moist indoor air meeting cold glass or an uninsulated light shaft can drip, which often gets mistaken for a leak. Building Code clause E2 expects concealed spaces to be built so moisture doesn't build up and cause condensation or mould, so ask how the shaft will be lined and insulated.
Sunshine and summer heat
The south-west tip of the region gets over 2,100 hours of bright sunshine a year, and NIWA's summer UV forecasts for Wellington prompt sun protection warnings through most of the day. A skylight lets in heat and UV along with light, so glazing choice affects how a room feels in January.
Your wind zone still applies
Wellington City Council publishes wind zones for its urban areas based on NZS 3604:2011. Ask whether the skylight and its fixings suit your site's zone, especially on an exposed ridge-top section.
Consent, and who should fit it
Swapping an old skylight for a comparable one in the same spot is the kind of like-for-like replacement that Schedule 1 of the Building Act can exempt from consent. A brand-new skylight that means cutting rafters or trusses touches the structure, so ask your roofer whether it needs a building consent, and check with Wellington City Council if in doubt.
If it does need consent, the roofing part is likely to be restricted building work, which an LBP must carry out or supervise. Either way, pick someone who fits skylights in your type of roofing regularly.
What you can do, and what needs a roofer
You can
- Note whether drips appear only in rain (likely a leak) or on cold, dry mornings (likely condensation)
- Run extractor fans and open windows to cut indoor moisture in winter
- Clean the inside of the glazing from a stable stepladder indoors
- Photograph stains and drips with the date, for the roofer
Leave to a roofer
- Anything on the roof, including cleaning the outside of the skylight
- Checking and replacing flashings and seals
- Cutting a new opening and framing it
- Lining and insulating the light shaft
What makes a skylight job bigger or smaller
Swapping a like-for-like unit on a longrun roof sits at the simpler end. Cutting a new opening, working on a tile roof, a deep ceiling space that needs a long light shaft, an electric unit or blinds, glazing upgrades for hail or heat, and awkward access all add work.
A quote worth signing names the unit and its size, the flashing kit, how the shaft will be lined and insulated, and whether making good the ceiling inside is included.
Ask these before you choose a skylight
- Which flashing kit suits my roofing profile, and how is it sealed?
- Is the unit rated for my wind zone, and how is it fixed down?
- What glazing do you recommend for hail and summer heat?
- How will the light shaft be lined and insulated against condensation?
- Will this need a building consent?
- What maintenance keeps the warranty valid?
Our view on skylights in Wellington
We'd spend the money on a proper flashing kit and an insulated shaft before an electric opening unit. If there's a choice of spot, we'd keep it away from valleys and the most exposed edge of the roof. And on a leak, we'd want the flashing checked first, because replacing a sound skylight won't stop water getting in around it.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.