What happens behind the cladding matters as much as what you can see.
Facade cavities can help drain water, ventilate moisture and separate layers. Without correct geometry, compartmentation and fire barriers, the same concealed space can create a route for rapid hidden spread.
The space behind the outer skin is a working part of the facade system.
A facade cavity is the space between the external cladding and the backing wall, insulation or membrane. In a rainscreen arrangement, it can allow water that passes the outer joints to drain and may also support ventilation and drying.
The same space can become a concealed path for smoke, hot gases and flame when it remains continuous across floors, corners, openings or compartment lines. Cavity width, ventilation openings, subframes, insulation, membranes and barriers must therefore be designed together.
See how the cavity connects the outer skin with the layers behind it.
Open →Understand why assembly behaviour matters more than one product claim.
Open →PE, FR, A2 and A1 terminology without confusing panel and system performance.
Open →Product tests and full-scale facade tests answer different questions.
Open →The concealed space between the outer skin and the backing construction.
Open →Why water paths, openings and clear routes matter behind rainscreen cladding.
Open →Ventilation can support drying but must be coordinated with fire compartmentation.
Open →Continuous vertical spaces can channel heat, smoke and flame upward.
Open →Barriers are intended to interrupt concealed spread at defined locations.
Open →Windows, slab edges, parapets, corners and material changes require coordination.
Open →Insulation, membranes and backing walls influence moisture and fire behaviour.
Open →Concealed work must be checked before cladding closes the cavity.
Open →Material performance is not cavity performance.
A non-combustible, A1, A2, FR or otherwise classified product does not, by itself, describe the behaviour of the complete facade. The cavity may connect combustible materials, insulation, membranes, joints and openings in ways that change the system response.
The correct question is not only “What is the cladding?” but also: “What is behind it, how is the cavity divided, where can air and water move, and what evidence represents the complete assembly?”