75mm vs 100mm Insulated Aluminum Roof Panels: Which Thickness for Your Project?

The most common question from first-time buyers of insulated aluminum Great Wall panels is whether to specify 75mm or 100mm core thickness. The wrong choice costs money — either in upfront overspecification or in long-term energy bills. This guide gives you the decision framework used by experienced contractors across the Middle East and Southeast Asia.

The Core Difference: Thermal Resistance

Both 75mm and 100mm panels use PIR foam core with thermal conductivity λ ≤ 0.022 W/(m·K). The difference is the R-value (thermal resistance) they provide:

Thickness	R-value (m²·K/W)	Interior temp reduction*	Typical application
50mm	R-2.3	6–8°C	Open sheds, low-budget builds
75mm	R-3.4	10–13°C	Standard warehouse, factory (most common)
100mm	R-4.5	13–16°C	Logistics, pharma, food, temperature-sensitive
150mm	R-6.8	17–20°C	Cold storage, blast freezers

*Compared to uninsulated steel sheet, under Saudi/UAE summer conditions. Actual results vary by building design and ventilation.

Choose 75mm When:

• Building is a dry warehouse or general cargo store — ambient temperature goods (auto parts, building materials, textiles)
• Budget is the primary constraint — 75mm panels cost approximately 15–20% less than 100mm for the same area
• Interior temperature of 35–40°C is acceptable — workers are not present continuously, or goods are not heat-sensitive
• Project is in an area with relatively mild summer temperatures (e.g. northern Vietnam, highlands of Indonesia)

Choose 100mm When:

• Building will store temperature-sensitive goods — pharmaceuticals, electronics, food products
• You are running air conditioning inside the building — the thicker panel reduces compressor load by 25–35% compared to 75mm, typically recovering the cost difference within 2–3 years
• The building is in a Saudi Arabian or UAE coastal zone with extreme solar load and salt-laden air
• Workers are present during the full working day — occupational health standards in GCC countries increasingly require maximum interior temperatures
• You are specifying for a food or pharmaceutical facility — most food safety audits (BRC, FSSC 22000) require demonstrating temperature control, which is easier to certify with 100mm panels

Price Difference: Is 100mm Worth It?

For a 5,000m² project, the upfront cost difference between 75mm and 100mm panels is typically USD 8,000–15,000 (depending on aluminum face gauge and coating). Against this, the energy saving from reduced A/C load typically runs USD 4,000–8,000 per year in Saudi or UAE conditions. The payback period is 1–3 years — after which the 100mm option generates ongoing savings for the lifetime of the building.

For buildings without air conditioning, the payback calculation does not apply — in that case, choose 75mm unless your goods or process specifically require the cooler interior.

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