Plastic roofing sheets are lightweight, semi-translucent panels used to cover patios, carports, greenhouses, sheds, and pergolas where you want daylight and weather protection without the cost of glass or a full framed roof. The two materials most people compare are polycarbonate and PVC, with corrugated fiberglass (GRP) and PET as secondary options. Polycarbonate costs more but resists impact and heat far better; PVC is the budget pick for low-stress, short-life covers. Installed material cost typically runs $1.50 to $12 per square foot depending on type and thickness.
This guide breaks down each type, real US pricing per square foot, the thickness you actually need for your structure, and where plastic sheets make sense versus corrugated metal for the same carport or patio job.
What are plastic roofing sheets and where are they used?
Plastic roofing sheets are rigid or semi-rigid panels made from polycarbonate, PVC, PET, or fiberglass-reinforced plastic that let filtered light through while shedding rain and snow. They weigh a fraction of glass or metal, cut with common tools, and screw down to timber or steel purlins. Most are sold in flat solid sheets, hollow multiwall panels, or corrugated profiles that match standard metal panel spacings.
The common jobs are accessory structures, not primary house roofs. Typical uses include patio covers and verandas, freestanding and lean-to carports, hobby and commercial greenhouses, garden sheds, pergolas, covered walkways, and industrial rooflights that bring daylight into a metal building. For a full framed patio structure rather than just the covering, see our guide to an attached gable roof patio cover.
Types of plastic roofing sheets compared
There are four plastic roofing materials in common use: polycarbonate (solid and multiwall), PVC, PET, and fiberglass-reinforced plastic (GRP). They differ most in impact strength, heat tolerance, light transmission, and how long they last outdoors before yellowing or going brittle. The table below compares them on the specs that decide a purchase.
| Material | Impact resistance | Light transmission | Typical lifespan | Best for |
|---|---|---|---|---|
| Solid polycarbonate | Very high (roughly 200x acrylic) | Up to 90% clear | 10 to 20 years | Carports, patios, security glazing |
| Multiwall polycarbonate | High | Around 55 to 80% by wall count | 10 to 20 years | Greenhouses, insulated patio roofs |
| PVC (corrugated) | Low to moderate | Around 50 to 75% | 5 to 10 years | Sheds, temporary or budget covers |
| PET | Moderate to high | Up to 90% clear | 10 to 15 years | Recyclable clear covers, canopies |
| Fiberglass (GRP) | Moderate | Around 70% translucent | 10 to 15 years | Industrial rooflights, agricultural |
Polycarbonate roofing sheets
Polycarbonate roofing sheets are the strongest common plastic option, with impact resistance roughly 200 times that of acrylic and about 20 times that of glass, so they resist hail and dropped tools without shattering. They handle service temperatures from about minus 40 to 250 degrees Fahrenheit and carry a UV-protective coating on the weather side to slow yellowing. Solid sheets deliver up to 90% light transmission; multiwall panels trap air for insulation but transmit less light.
Polycarbonate is the default for carports, patio roofs, and quality greenhouses because it takes abuse and lasts 10 to 20 years. The trade-off is price and expansion: it moves more with temperature than PVC, so oversized screw holes and proper foam closures matter at install.
PVC roofing sheets
PVC roofing sheets are the budget choice, usually corrugated, and cost the least per square foot of any common plastic panel. They resist many chemicals and are easy to cut and screw down, which makes them popular for sheds, lean-tos, and short-term covers. The trade-off is durability: standard PVC has lower impact strength, tolerates less heat, and often yellows or turns brittle within 5 to 10 years, sooner in strong sun.
PVC as a rigid sheet is a different product from the PVC single-ply membrane used on commercial flat roofs. If you are pricing a welded flat-roof membrane instead of a translucent sheet, see our PVC roof cost guide.
PET and fiberglass (GRP) sheets
PET and fiberglass sheets fill the middle of the range. PET (the same polymer as drink bottles) is clear, recyclable, and reasonably impact resistant, often sold as an eco alternative to polycarbonate for canopies. Fiberglass-reinforced plastic (GRP) is a corrugated translucent sheet with an industrial look, common on agricultural buildings and rooflights, lasting 10 to 15 years but prone to surface fiber bloom as it ages.
How much do plastic roofing sheets cost?
Plastic roofing sheet material typically costs $1.50 to $12 per square foot, with corrugated PVC at the low end and thick multiwall polycarbonate at the top. Price scales with thickness, wall structure, and UV coating quality. The figures below are US material-only ranges; add fixings, flashing, framing, and labor if you are not installing yourself.
| Sheet type | Typical thickness | Material cost per sq ft |
|---|---|---|
| Corrugated PVC | 0.8 to 1.5 mm | $1.50 to $3.50 |
| Corrugated polycarbonate | 0.8 to 1.2 mm | $2.00 to $4.50 |
| Solid polycarbonate | 4 to 8 mm | $2.50 to $6.00 |
| Multiwall polycarbonate | 6 to 25 mm | $5.00 to $12.00 |
| Fiberglass (GRP) | 0.8 to 1.2 mm | $2.00 to $4.00 |
A common 8 ft by 4 ft corrugated sheet runs roughly $30 to $70. Buying the cheapest sheet is often false economy: a corrugated PVC panel that lasts 5 years can cost more per year of service than a 20-year corrugated polycarbonate panel, once you factor in the labor to tear off and re-cover.
What thickness of plastic roofing sheet do I need?
Thickness depends on the structure, the purlin spacing, and your snow load, not just the panel size. For most patios, carports, and pergolas, 10 mm multiwall polycarbonate is the sweet spot. Corrugated sheets for the same jobs should be a quality UV-coated profile with purlins no more than about 24 inches apart. In heavy-snow regions, step up to 16 mm or 25 mm multiwall.
- Patio or veranda roof: 10 mm multiwall polycarbonate balances light, insulation, and span. Move to 16 mm for enclosed verandas.
- Carport: 10 mm multiwall or a corrugated polycarbonate profile over 24-inch purlins handles typical loads and hail.
- Greenhouse: 6 mm twinwall for hobby greenhouses, 8 mm or 10 mm where weather is harsher, for insulation and diffusion.
- Shed or temporary cover: corrugated PVC or 4 mm solid where budget beats longevity and impact risk is low.
- Heavy snow load: 16 mm or 25 mm multiwall, with closer purlin spacing per the manufacturer span chart.
Plastic sheets vs corrugated metal for a carport or patio
Choose plastic sheets when you want daylight through the roof and easy DIY handling; choose corrugated metal when you want maximum lifespan, fire resistance, and a solid opaque roof. Plastic wins on light transmission, weight, and cut-to-size flexibility. Metal wins on 40-plus year lifespan, no yellowing, and structural rigidity. Many carports use both: metal for the main roof and a run of clear polycarbonate for a daylight strip.
If you are weighing an opaque metal cover instead, compare sizes and pricing in our guide to corrugated roof panels. For a translucent alternative that behaves more like a fixed roof window over a living space, see how skylight installation cost compares.
Installation and maintenance basics
Plastic roofing sheets install over purlins with self-tapping screws fitted with sealing washers, always through the crown of a corrugation, not the valley, so water drains past the fixing. Polycarbonate expands and contracts with temperature, so pre-drill oversized holes and never overtighten. Lay sheets with the UV-coated face up, follow the manufacturer overlap, and seal end caps on multiwall panels to keep dust and insects out of the flutes.
Maintenance is light. Rinse sheets with water and a soft brush, avoid abrasive pads or solvent cleaners that scratch or cloud the surface, and clear leaves so trapped moisture does not stain. Walk on a scaffold board spanning the purlins, never directly on the sheet, since even impact-resistant panels can crack under a point load. To place plastic roofing in the wider material picture, browse our roofing knowledge hub.
Which plastic roofing sheet should you choose?
For a roof you want to last and take abuse, choose polycarbonate; for the cheapest short-term cover, choose PVC. Pick multiwall polycarbonate for patios and greenhouses where insulation and light diffusion matter, solid polycarbonate where you want maximum clarity, and corrugated PVC only for low-stress budget jobs like a shed. Match the profile to your existing purlin spacing, and always buy UV-coated sheets so the roof does not yellow within a few seasons.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.