CORROSHIELD® Fasteners POLYTAPP® Skylight Fixing Screw
When fixing skylights, the fastening point is also the highest risk point—overtightening, sheet damage, and leaks can lead to costly callbacks. POLYTAPP® Skylight Fixing Screws are designed specifically for crest fixing skylight polycarbonate sheets, allowing the screw to grind a pilot hole on the sheet before engaging the steel or timber substrate.
This controlled fixing action supports cleaner installation, better sealing performance, and dependable long-term holding.
Specification
Material: Carbon Steel
Head Type: Hex Washer Flange
Thread: Partial Thread with POLYTAPP® Wing
Drill Point: LEVIN® Drill Point
Drilling Capacity: Max 5.5mm steel
Washer: Dome Washer
Fixing Type: Only for Crest Fixing
Best-Fit Applications
Recommended for:
Polycarbonate skylight sheets on metal roofing systems
Fibreglass skylights
Crest fixing applications on roofing profiles
Substrates:
Steel purlins
Timber substrates (POLYTAPP® category is for skylights to steel or timber)
Why POLYTAPP®
/1
Pilot-hole forming wing = safer skylight fixing
POLYTAPP® is built with a POLYTAPP® wing that helps create a pilot hole in the skylight sheet—supporting more controlled fastening on brittle/translucent materials.
/2
Water sealing with dome washer
Supplied with a dome washer to improve weather sealing on skylight crest fixing points and help protect the sheet around the fastener.
/3
Fast installation with reliable drilling
Powered by a LEVIN® Drill Point for faster engagement and smoother drilling performance.
/04
Designed to reduce pull-over risk
Engineered for improved pull over performance—important where skylight sheets require stable clamping without damage.
Fastener Types
How It Works
Step-by-step fixing concept:
Position the screw on the crest of the polycarbonate skylight sheet.
Allow POLYTAPP® to grind a pilot hole in the skylight sheet.
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As the screw continues into the steel substrate, the wings break off and the fastener seats with the washer system for sealing.
Quality & Performance You Can Specify With Confidence
POLYTAPP® is part of a premium fastening system built for demanding construction environments, supported by:
Coating technology developed for corrosion resistance performance requirements aligned to international standards (ASTM / AS / BS / EN as referenced in the catalogue)
In-house QC processes and testing capabilities (hardness, drill tests, corrosion resistance testing, dimensional checks)
How to Select the Right POLYTAPP® Screw?
Identify the material type – Choose the POLYTAPP® screw based on the plastic, polycarbonate, or lightweight sheet material being fixed.
Select the correct thread design – Ensure the thread profile is suitable to prevent cracking, stripping, or deformation of plastic substrates.
Check thickness & fixing depth – Match the screw length to the sheet thickness and support to achieve a secure yet stress-free fixing.
Consider sealing & exposure – Use sealing washers or UV-resistant options for outdoor applications to maintain durability and weather protection.
Installation guidelines (best practices)
Use a suitable screw gun and drive perpendicular to the sheet.
Fix only at the crest as recommended for skylights.
Tighten until the washer is securely seated for sealing—do not overdrive.
For steel purlins: ensure substrate thickness supports correct wing break-off action (≥ 1.6mm as noted).
Get Pricing & availability for POLYTAPP®
Frequently asked questions
POLYTAPP® is specified in the catalogue as only for crest fixing.
It is shown for polycarbonate skylight sheets, and the applications chart also indicates polycarbonate or fibreglass skylights.
The brochure notes: the wing will only break off if the steel substrate is at least 1.6mm thick.
POLYTAPP® comes with a 25mm dome washer for sealing support.
