Polycarbonate is the clear plastic used in skylight domes, flat roof light panels and the translucent sheets you see in shed and factory roofs. It weighs a fraction of glass, flexes instead of shattering, and can be moulded or rolled to match a roof profile, which makes polycarbonate skylights in Wellington a sensible choice for homes and workshops alike. For a home with an old dome that has gone cloudy, or a workshop with tired roof lights, it is often the most practical way to bring daylight back in.
In Wellington, those qualities matter. Gusts drive grit, twigs and hail across a roof, and a dome that cracks in a southerly lets water straight into the ceiling. Good polycarbonate takes that kind of knock far better than ordinary glass. It does have trade-offs: it scratches, it moves with heat, and cheap sheet without proper UV protection turns yellow. Below we explain where it works, where glass is better, and how we fit it.
Polycarbonate skylights are impact-resistant and lighter than glass, making them practical for sheds, garages, carports, verandas and many residential or light commercial roofs, with clear communication and fair upfront pricing.
Translucent polycarbonate sheets match corrugated and trapezoidal profiles, allowing natural light into workshops and covered areas while integrating neatly with the surrounding metal roofing, using quality materials and proven methods.
Polycarbonate is a cost-effective way to brighten dark spaces. UV-stabilised sheets resist yellowing and weathering, giving dependable light transmission for many years with minimal upkeep, for Wellington homeowners and businesses.
Neither material wins on every count. The choice usually comes down to where the skylight sits, what the room is used for, and whether you value a perfectly clear view of the sky over toughness and low weight.
Solid polycarbonate is far harder to break than standard glass, which is why it suits domes on exposed roofs, sites under trees and buildings where stray balls or vandalism are a concern. It flexes under a blow rather than cracking.
Glass stays optically clear and resists scratching. Polycarbonate is softer, so abrasive cleaning, grit and branches leave fine marks over time. Where you want a sharp view of the sky from a living room, glass is usually the better pick.
Polycarbonate is light enough to mould into domes and pyramids and to roll into corrugate or trapezoidal profiles. That makes it ideal for lightweight roof structures and for roof lights that sit in line with metal sheeting.
Single-skin sheet loses heat quickly and can feel hot under summer sun. Twin-wall and multi-wall sheet, or double-skin domes, trap air between layers and perform much better. Opal and tinted finishes cut glare in north and west-facing rooms.
Overhead glass must be toughened or laminated so a broken pane stays out of the room below. Polycarbonate does not shatter into shards, which is one reason it is chosen for domes over stairwells, hallways and other spots where people walk underneath.
Glazed roof windows are widely available as opening units with fitted blinds, rain sensors and matched flashing kits. Polycarbonate mostly comes as fixed domes and sheeting, so for a skylight that vents or takes a blind, glass gives more choice.
Many skylight domes fitted to Wellington homes in the 1970s and 80s were acrylic or early plastics without an effective UV-protective layer. Years of sunlight break down the surface, so the dome yellows, goes chalky and loses its strength. A brittle dome can crack when a gust flexes the frame or when someone leans a ladder against it, and the first sign is often a stain on the ceiling below.
Modern polycarbonate sheet is made with a co-extruded UV-protective layer on the weather side. That layer is what keeps the sheet clear, and it only works if the sheet goes in the right way up, so we check the marking on every sheet before it is cut and fixed. How long any plastic glazing stays clear still depends on exposure and maintenance, and manufacturer warranties vary by product.
On sheds, workshops, warehouses and carports, polycarbonate roof lights are usually profiled sheets that lap in with the surrounding metal roofing. Getting the detail right is what stops them leaking at the laps or cracking around the fixings.
We match the clear sheet to the existing roof profile, whether corrugate or a trapezoidal rib, so side laps sit tight and water runs off without ponding or wicking back at the joins.
Clear sheet lets in the most light but can cause glare and heat build-up over a workbench or stored stock. Opal or tinted sheet spreads the light more evenly, which many workshops and farm sheds find easier to work under.
Polycarbonate expands and contracts more than steel. We pre-drill oversized holes and use fixings with suitable sealing washers, tightened enough to seal without crushing the sheet. Over-tightened screws are a common cause of cracks radiating from fixings.
Foam profile fillers shaped to the sheet close the gaps under the ribs at the ridge and eaves. On an exposed Wellington site they stop gusts driving rain, dust and nesting birds in under the clear sheets.
Some solvent-based sealants and cleaners attack polycarbonate and cause crazing. We use products the sheet manufacturer approves and detail the surrounding metal to the NZ Metal Roof and Wall Cladding Code of Practice.
Clear sheeting is not designed to be walked on. Anyone on the roof must treat roof lights as fragile, and on larger buildings we discuss mesh or guards. Our commercial roof lights page covers fall-through protection in more detail.
Polycarbonate is strong, light and affordable, making it a practical choice for sheds, garages, carports, verandas and many light commercial roofs. Our installers supply UV-stabilised sheets that match your roofing profile, whether corrugated, trapezoidal or flat, and fix them with the correct washers and sealing so they stay watertight. We allow for thermal expansion, which is often overlooked and leads to cracking or leaking in cheaper installations. Wellington's wind is also considered, with secure fixings placed correctly across each sheet. Panels transmit plenty of natural light, resist impact and weather well, and need very little upkeep, giving you dependable daylight at a sensible price. Talk to our friendly team about your project.
Polycarbonate is one glazing option among several. Our main skylight page covers the full range of work we do, and these pages go deeper on closely related jobs.
Call our team if you need advice for your property or roofing project.
04 888 0115Not for long. Yellowing in old acrylic and unprotected plastic is a breakdown of the material itself, not surface dirt. Polishing may remove some haze, but it strips whatever surface protection remains and the dome is still brittle underneath. If a dome is yellow, chalky or showing fine cracks, skylight replacement with a UV-protected polycarbonate dome is the sensible fix, checking the upstand and flashings at the same time.
No. Even thick polycarbonate roof lights should be treated as fragile. Sheets weaken with age and UV exposure, and a foot placed between purlins can go straight through. WorkSafe guidance on working at height treats fragile roof surfaces as a serious fall risk. Clean and inspect from a safe position, and on larger roofs consider mesh under the sheets or guards over them.
Rain is more audible on single-skin sheet than on glass. Twin-wall or multi-wall polycarbonate and double-skin domes are noticeably quieter because the air gap dampens the drumming. If the skylight is over a bedroom and Wellington's heavy downpours would bother you, factor that in, and consider whether a glazed unit is the better choice for that room.
Use lukewarm water, a mild detergent and a soft cloth or sponge, then rinse well. Avoid abrasive pads, scrapers, solvents, ammonia-based glass cleaners and close-range water blasting, all of which can scratch the surface or damage the UV layer. On coastal properties from Eastbourne to Plimmerton, a gentle rinse a couple of times a year helps clear salt build-up.
Usually, yes. If the surrounding metal roofing is in reasonable condition, we remove the old clear or fibreglass sheets and fit new polycarbonate in a matching profile. If the steel next to the roof lights is rusting at the laps or fixings, it can make more sense to replace those sheets at the same time, and we will point that out in your written quote.
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