Short answer
A roofing sheet keeps rain out: it is usually pre-painted (PPGI) in white, off-white or beige, with narrow ribs standing up and wide pans between them. A decking sheet is a permanent floor formwork: it is plain silver galvanized, with deep, wide profiles, and concrete is poured on top of it.
Side-by-side
| Roofing sheet | Decking sheet | |
|---|---|---|
| Job | Roof and wall cladding | Composite floor slab (concrete on top) |
| Typical finish | Pre-painted PPGI: white RAL 9010, off-white RAL 9002, beige RAL 1001 | Plain galvanized, silver |
| Profile | Narrow raised ribs, wide flat pans | Deep trapezoid with wide flat tops |
| Fixing | Screws with washers through the rib crowns into purlins | Shear studs or fixings to steel beams |
| End lap | Laps on roof slope | Butt or lap over supports |
Why colour matters on a UAE roof
Light colours reflect more of the sun. White and off-white roofs stay cooler than dark roofs, which reduces heat gain into the building. That is why most UAE industrial roofs are white or off-white.
Before you order
- Confirm the profile (rib height and cover width) from the drawing.
- Confirm sheet thickness and coating (zinc mass, paint system).
- For decking, confirm the slab design: span, concrete depth and stud layout.
- Use the free calculator to estimate the number of sheets and laps.
Frequently asked questions
Can I use a decking sheet as a roof?
It is not designed for that. Decking sheets are thicker and deeper for carrying wet concrete; a roofing sheet with the right paint system weathers better and costs less per square metre.
What does PPGI mean?
Pre-Painted Galvanized Iron: galvanized steel coil that is painted in a factory line before it is roll-formed into sheets.