This glossary defines the technical terms used for insulated aluminum Great Wall panels (长城瓦 / 长城隔热铝瓦) — the products GSM BuildTech manufactures factory-direct in Tianjin, China. Every term below relates to the aluminum-faced insulated roof and wall panel and how to specify, order and install it.
Related: technical reference & FAQ · panel vs alternatives · how to order from China.
Glossary of insulated aluminum Great Wall panel terms
Great Wall panel (长城瓦)
An insulated aluminum sandwich panel with a corrugated ‘Great Wall’ profile outer face, named for its resemblance to the crenellations of the Great Wall. Used for roofing and wall cladding on industrial buildings. Also called 长城隔热铝瓦, insulated Great Wall aluminum panel, or Great Wall tile.
Insulated aluminum roof panel
A one-piece roof panel with PVDF-coated aluminum faces bonded to a PU or PIR foam core (50–200mm). Provides structure, weatherproofing and thermal insulation in a single component, unlike a single-skin metal sheet.
PVDF coating
Polyvinylidene fluoride (Kynar 500 class) paint finish on the aluminum face. Highly UV- and chalk-resistant, carrying a 20-year color warranty including C4 coastal exposure. The standard coating on GSM BuildTech Great Wall panels.
PU core
Polyurethane rigid-foam insulation core, fire class B2. The standard, cost-effective core for insulated aluminum Great Wall panels.
PIR core
Polyisocyanurate rigid-foam core, fire class B1. An upgrade over PU that chars instead of melting and holds compressive strength slightly better; chosen where B1 is required by code or insurer.
Core density
The mass of foam per cubic metre of panel core, typically 42–45 kg/m³ for GSM BuildTech panels. Higher density means better compressive strength, dimensional stability and stable thermal performance.
U-value
The rate of heat transfer through the panel, in W/m²K — lower is better. Ranges from about 0.29 (75mm) to 0.11 W/m²K (200mm) for insulated aluminum Great Wall panels.
Aluminum face
The 3003-H14 aluminum outer/inner skin of the panel, 0.4–1.0mm thick. Unlike galvanized steel it does not rust, making it suited to coastal, humid and washdown environments.
Sandwich panel
A composite panel of two metal faces bonded to an insulating core. An insulated aluminum Great Wall panel is a type of sandwich panel using aluminum faces and a PU/PIR core.
Purlin spacing
The distance between the secondary steel members (purlins) that support the roof panels. Correct spacing depends on panel thickness, span and wind-uplift load, and is set per project.
Standing seam vs through-fix
Two fastening methods. Through-fix screws pass through the panel face (simple, allows single-panel replacement); standing seam conceals fixings under a raised seam (better for wind-driven rain). Great Wall panels are commonly through-fixed.
Ridge cap
The trim that covers the apex where two roof slopes meet, closing the roof against rain. Supplied as a matched accessory with Great Wall panels.
Flashing
Shaped metal trims that seal panel edges, junctions and penetrations against water. Part of the accessory package (typically 8–12% of panel value).
Daylight panel
A translucent polycarbonate panel rolled to the same Great Wall profile so it laps and fixes like the aluminum panels, providing natural light without a separate opening. Usually 3–5% of roof area.
B1 / B2 fire class
European reaction-to-fire classes for the core. B2 is standard (PU); B1 is the upgrade (PIR). For non-combustible A1/A2 fire walls a mineral wool core is required.
MOQ
Minimum order quantity — one 40ft container, roughly 300–400 m² of finished Great Wall panel depending on thickness.
FOB / CIF
Incoterms. FOB (Free On Board) prices the panel to the ship at Tianjin/Xingang; CIF (Cost, Insurance, Freight) prices it delivered to your destination port. Both are quoted factory-direct within 24 hours.
Form E / SABER
Export documents that reduce import cost. Form E is the ASEAN certificate of origin cutting duty under ACFTA; SABER is Saudi Arabia’s product conformity requirement. Both are provided where applicable.
Need a spec or quote? Email sales@insulatedaluminumroof.com or WhatsApp +86 155 2274 6824 — FOB or CIF within 24 hours.