Sourcing polycarbonate roofing screws from a trusted manufacturer? Sinsun offers one-shot self-drilling screws with EPDM sealing washers for timber and metal frames. Browse size charts, coating options, and bulk pricing.
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| Coating Type | Corrosion Rating | Typical Application |
| Electro‑zinc / Zinc‑plated | Standard interior/dry condition | Covered carports, indoor atriums, low‑humidity environments |
| Class 3 / Class 4 hot‑dipped galvanized | 500–1,000 hours salt spray | General exterior roofing, standard residential and agricultural |
| Ruspert triple‑layer coating | 1,000+ hours salt spray | Coastal installations within 10 km of salt water, industrial zones |
| 304 Stainless Steel | Excellent for mild coastal and chemical exposure | Food processing, pharmaceutical, high‑moisture interiors |
| 316 Stainless Steel (Marine Grade) | Maximum saltwater resistance | Dockside structures, marine buildings, direct ocean exposure |
| Size | Length Range | Point Type | Head Style | Washer Type | Coating Options | Substrate Application |
| #8–#9 | 25mm – 45mm (1″ – 1-3/4″) | Type 17 (sharp) | Hex Washer | Domed EPDM | Zinc‑plated, Class 3 | Timber frames, thin polycarbonate panels |
| #10 | 38mm – 50mm (1-1/2″ – 2″) | One‑Shot cutter / Type 17 | Hex Washer / Pan | Domed EPDM / Sealing Dome | Class 4, Ruspert, 304SS | Timber purlins, standard corrugated sheets |
| #12 | 50mm – 75mm (2″ – 3″) | One‑Shot cutter / TEK 2–3 | Hex Washer | Domed EPDM | Class 4, Ruspert, 304SS, 316SS | Timber or light‑gauge steel purlins |
| #14 | 65mm – 100mm (2-1/2″ – 4″) | TEK 3–4 (self‑drilling) | Hex Washer | Domed EPDM | Ruspert, 316SS | Heavy steel purlins, structural framing |
| M4.8 (4.8mm) | 25mm – 100mm | One‑Shot cutter / Type 17 | Hex Washer | Domed EPDM | Class 4, Ruspert | Polycarbonate to wood or steel |
| M5.5 (5.5mm) | 50mm – 150mm | TEK 3 / One‑Shot cutter | Hex Washer | Domed EPDM | Class 4, Ruspert, 304SS | Commercial polycarbonate roofing, thick profiles |
Our polycarbonate roofing screws are suitable for residential applications such as awnings, patios and small greenhouses. They attach polycarbonate sheets to wood or steel framing without cracking, a typical issue with generic screws. Our high-quality screws for polycarbonate roofing are trusted by homeowners and DIYers for their easy installation and leak-proof seal. Our unique design makes screwing polycarbonate sheets easy, saving time and money on panel replacements.
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The corrugated polycarbonate roofing screws are suitable for applications in agricultural shelters and commercial greenhouses.Corrugated polycarbonate panels should be perfectly matched by these screws.This is so that when they are attached, they make a tight seal that keeps moisture out but lets sunlight in. We make them with UV resistant washers that can take the long term sun, without getting brittle and leaking.Because these screws last a long time and help speed up the installation process, contractors love them for greenhouse projects.
Get a Quick QouteBastion polycarbonate roofing screws and one-shot polycarbonate roofing screws are for heavy-duty industrial and commercial roof applications. They attach thick polycarbonate panels to the steel purlins, which resist wind uplift and vibration. The reinforced shanks of these polycarbonate roof fasteners prevent pull-out even in heavy traffic or harsh working environments. We customize these screws for large commercial buildings, warehouses and industrial facilities.
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Polycarbonate sheet screws are suitable for Do-It-Yourself projects such as garden sheds, carports and window awnings. The blunt tip and soft washer protect delicate polycarbonate sheets from damage, and are suitable for beginners. Installation of one-shot models requires no predrilling, and standard tools are all that are needed. These screws make it easy to screw in polycarbonate roofing. They are popular because they are affordable and reliable for small projects.
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The required screw length depends on the corrugated panel profile height plus the thickness of the substrate penetration. For a typical corrugated polycarbonate panel with an 18mm–25mm crest height, use a polycarbonate roofing screw length that reaches through the crest and at least 25mm into the timber. This is done through three full threads into the steel.
Formula: Screw length = Panel crest height + Substrate penetration allowance (wood: 25mm, steel: 3 thread pitches). Using a 50mm screw on a timber purlin with a crest height of 20mm, there is a safe margin of 20mm + 30mm.
Place the polycarbonate panel on the roof frame with the UV-protective film side facing up.
Arrange the panels so that the corrugated crests sit neatly on the purlins.
Place the screw head at the top of a rib and perpendicular to the face of the panel.
Set drill to low speed (max 1,800–2,000 RPM). The cutter is burning at higher speeds.
Apply a little pressure forward. The cutter will touch the sheet and make an expansion hole of 10mm.
The cutter clears the sheet and the screw threads engage the substrate. Drive until you barely touch the panel crest with the domed EPDM washer and see compression.
Stop running when the washer is slightly flattened on the outside edge but NOT squeezed out past the edge of the head.
| Panel Location | Screw Spacing |
| Along panel laps and overlaps | 150–300mm (6–12 inches) |
| Interior field areas (away from edges) | 300–600mm (12–24 inches) |
| Eaves, ridges, and gable ends | 150mm (6 inches) maximum |
| First and last purlins | Fasten every corrugation crest |
“For industrial polycarbonate roofs, we use Sinsun's Bastion polycarbonate roofing screws. We needed fasteners to hold thick multi-wall panels to steel purlins, and these did the job. They are resistant to wind-uplift and corrosion, even in humid industrial environments.They provide a clean finish and hold tight for many years.Quality control is top notch at the factory. Every batch is the same.
“We are a DIY supplier, so we have Sinsun's polycarbonate sheet screws and the finest screws for polycarbonate roofing – they are our most popular sellers. Canadian homeowners love how easy they are to install on small projects like patios and garden sheds. Customer rave that these screws stop panel cracks. This was a huge complaint with other brands. “We’re getting repeat orders month after month and Sinsun’s factory support is great – custom sizes come quickly when we need them.”
A: They go by several names: polycarbonate sheet screws, polycarbonate roof fasteners, polycarbonate roof panel fasteners, screws for polycarbonate panels, or simply polycarbonate screws. Some products carry trade names like One Shot polycarbonate roofing screws or Vortex Polycut screws.
A: The best screws for polycarbonate roofing combine three features: an integrated 10mm hole cutter for thermal expansion clearance, a domed EPDM sealing washer to prevent leaks, and a corrosion‑resistant coating matched to the environment (Class 4, Ruspert, or stainless steel).
A: Not without risk. Standard metal roofing screws lack the built‑in expansion cutter, so the hole they create is too tight for polycarbonate’s thermal movement. That confinement leads to cracking, buckling, or fastener pull‑through within a few seasons. Always use dedicated polycarbonate roofing screws.
A: With one‑shot polycarbonate roofing screws, no. The screw includes an integrated 10mm hole cutter that creates the necessary expansion clearance during driving. Traditional polycarbonate sheet screws require separate pre‑drilling with a 10mm bit, but we do not recommend that method for new installations.
A: For 4mm polycarbonate sheets on timber purlins, a #9 or #10 screw at 25mm–38mm length is appropriate. The specific length depends on your crest height and purlin depth. Our 38mm one‑shot screws cover most residential applications.
A: Both serve the same application—polycarbonate sheet attachment. Bastion is a well‑known brand in the Australian market. Sinsun offers comparable quality with direct factory pricing, integrated cutters, and Ruspert or stainless steel coatings. We compete on consistency, pricing, and the ability to customize for large orders.
A: Corrugated polycarbonate profiles—such as ROMA, GRECA, Timdek, and Beehive—use standard crest‑fixing screws with dome washers. Multiwall panels may require larger washers (1″ diameter) and different spacing. Confirm profile compatibility with your supplier before ordering.
A: Technically yes, but don’t. Different galvanic potentials can cause contact corrosion. Stick to one grade per roof.
A: For coastal installations within 10km of salt water, Ruspert triple‑layer coating or 304 stainless steel is recommended. For direct marine exposure or high chloride concentration, upgrade to 316 stainless steel.
A: The domed EPDM washer compresses against the polycarbonate crest as you drive the screw, forming a watertight barrier around the penetration. EPDM remains flexible across temperature extremes and resists UV degradation, unlike cheaper neoprene or foam washers.
A: Yes, but adjust your technique. PVC is more brittle than polycarbonate and cracks more easily under stress. Use the same expansion cutter screws, drive at even lower RPM, and be especially careful not to over‑tighten the washer.
A: For standard corrugated profiles on 900mm purlin spacing, estimate approximately 9 screws per square meter. At 600mm spacing, approximately 14 screws per square meter. Always include an extra 10% for waste and spacing adjustments.
A: Most bulk boxes include only the screws and washers. We recommend using a magnetic 5/16″ hex driver bit with a depth‑stop collar for consistent seating depth. We can supply driver bits as part of a factory order.
A: The most common causes are using a screw without the integrated expansion cutter, over‑tightening the fastener until the panel dimples, or driving screws while the protective film is still in place on the panel. Remove the film before installation, use one‑shot screws, and stop driving when the EPDM washer just begins to compress.
Whether you run a commercial greenhouse, a residential patio cover business, or a distribution warehouse, we deliver consistent quality at factory‑direct pricing. Our one‑shot polycarbonate roofing screws eliminate pre‑drilling, prevent thermal cracks, and seal tight for decades. Send me your specifications, and I will put together a bulk quote that outperforms anything your current supplier offers.
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