Jobsite installation engineering guide detailing minimum roof slopes (5-7%), end-lap cutbacks, thermal expansion movement, stainless bi-metal fasteners, and flashing watertightness.
Even the highest-grade sandwich panels will fail if installed with improper pitch, under-torqued fasteners, or reversed laps. Engineering watertightness requires strict compliance with roof slope minimums and bi-metal fastening.
1. Minimum Slope & Cold Cutting
Minimum slope is 5% for continuous single-length panels and 7% for end-lapped multi-panel runs. Never cut panels with abrasive angle grinders; use cold-cut nibblers or circular saws.
Comprehensive Engineering Comparison Matrix
| Parameter | Correct Standard | Risk if Neglected |
|---|---|---|
| Roof Pitch | Min 5% (single) / Min 7% (lapped) | Capillary back-flow and water pooling |
| Fastener Spec | Bi-Metal A2 stainless with EPDM saddles | Corrosion rust streaks and stripped threads |
| Cutting Method | Cold circular saw or nibbler | Abrasive sparks burn paint coating (rapid rust) |
Always specify bi-metal stainless screws with matching color saddles, and strip protective PE films immediately post-installation.
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Frequently Asked Questions
How many fasteners per square meter? ▼
Typically 3 to 4 fasteners per square meter, increased at building perimeter eaves and corner zones.