Short answer
Roofing sheet choice is two decisions stacked:
- Metallic / organic system — bare GI, bare GL (Galvalume), PPGI (paint on GI), or PPGL (paint on GL)
- Profile geometry — wave, trapezoidal / IBR-style, or tile-effect
Get both wrong and price comparisons are meaningless.
Start from the roofing sheet product family and the roofing profiles tool.
Decision table
| Option | What it is | Typical fit | RFQ must include |
|---|---|---|---|
| Bare GI | Zinc-coated sheet, metallic look | Mild climates, temporary works, later field paint, cost-sensitive cladding | Z/G coating mass, thickness, profile, length |
| Bare GL | Al-Zn coated sheet | Longer atmospheric exposure, many industrial roofs, solar-adjacent detailing | AZ coating mass, thickness, profile, length |
| PPGI | Paint system on GI substrate | Colored industrial/agricultural panels where GI substrate is accepted | Substrate coating + paint system + RAL + profile |
| PPGL | Paint system on GL substrate | Colored outdoor roofs where GL substrate is preferred | Substrate AZ mass + paint system + RAL + profile |
Deeper metallic comparison: GI vs Galvalume.
Deeper paint substrate comparison: PPGI vs PPGL.
Bare vs painted coil: PPGI vs galvanized coil.
Climate and detailing beat marketing labels
- Humid / long sea transit — packing and surface treatment matter as much as coating name (defect / white rust guide).
- Coastal or industrial atmospheres — raise coating mass and review fastener / cut-edge detailing; do not rely on color alone.
- Architectural color — lock RAL or sample, gloss, and batch rules via the RAL colors tool.
Profile first or coating first?
Buyers often argue about paint while the cover width and rib height are still open. That creates scrap and re-order risk at the roll former.
Minimum profile fields:
- Profile type (wave / trapezoidal / tile)
- Cover (effective) width
- Thickness
- Sheet length and packing
- Fastening notes if the buyer standard requires them
See profile RFQ fields on the profiles tool.
Coil vs sheet RFQ path
| If you buy… | Primary page | Notes |
|---|---|---|
| Mother coil for local roll forming | GI, GL, PPGI/PPGL | Specify coating then local profile drawing |
| Finished roofing sheet | Corrugated / trapezoidal roofing sheet | Specify profile + substrate + coating/paint together |
| Narrow feed for accessories | Galvanized strip | Slit width + coating mass |
RFQ template for roofing sheet
Product: Metal roofing / cladding sheet
Profile: wave / trapezoidal / tile (drawing attached if any)
Cover width: ____ mm
Thickness: ____ mm
Substrate: GI / GL / PPGI / PPGL
Coating mass: Z____ or AZ____
Paint system / RAL (if prepainted): ____ / RAL ____
Length: ____ mm (or container-optimized)
Quantity: ____ sheets or ____ t
Destination port: ____
Packing: seaworthy export packing
Documents: MTC ____ ; inspection photos ____Key takeaway
Choose roofing sheet by exposure + appearance + profile geometry, then write coating mass, paint (if any), and cover width on one RFQ. Comparing only “color sheet price” without profile and substrate is how projects buy the wrong coil twice.
