How thick should the insulation behind an aluminium panel be?

Insulation thickness behind a rainscreen is set by the thermal performance the building has to reach, not by the panel. What the panel does affect is the cavity: the ventilated gap behind the panel must stay open, so the insulation cannot simply be packed out to fill the zone. Bracket penetrations through the insulation carry far more heat than their area suggests, which is why thermal breaks at the bracket often matter more than the last ten millimetres of thickness.

Key points

• Insulation thickness follows the building's target thermal performance, not the panel type
• The ventilated cavity behind the panel must stay clear; insulation cannot fill the whole zone
• Bracket penetrations conduct disproportionately and often dominate the calculated result
• Thermal breaks at the bracket frequently deliver more than additional insulation thickness

Published by: Foshan Qi Aluminum Decorative Materials Co., Ltd.