For exterior windows, main frame and sash profiles of about 1.4–2.0 mm wall thickness are common; doors and large or high-wind openings need the thicker end, around 2.0 mm or more. Thinner walls (1.0–1.2 mm) save metal and cost but bend and loosen at joints. Specify the wall thickness of the main load-bearing sections on the order, and measure it with a caliper on delivery.
| Wall thickness | Typical use |
|---|---|
| 1.0–1.2 mm | Interior partitions, light frames, budget projects |
| 1.4 mm | Standard residential windows in low-wind areas |
| 1.6–1.8 mm | Residential and commercial exterior windows |
| 2.0 mm and above | Doors, large openings, high-rise and high-wind sites |
Standards
Chinese standard GB/T 8478 sets minimum wall thicknesses for the main profiles of exterior aluminium windows and doors; Europe and Australia test the finished window for wind load instead (EN 12210, AS 2047). Either way, thickness is checked on the main load-bearing sections.
Thickness is not everything
Section depth, the thermal break and the reinforcement of corners matter as much as wall thickness. A well-designed 1.6 mm section can outperform a poorly designed 2.0 mm one.
Questions
How do I check wall thickness?
Measure the main frame wall with a caliper away from the coating edges; coating adds a few hundredths of a millimetre.
Is thicker always better?
Thicker walls are stronger but heavier and dearer. Specify what the opening size and wind load need.