Steel conducts heat dramatically better than wood, so a metal-framed envelope lives or dies on continuous exterior insulation and an unbroken air barrier. This system documents the layer order that keeps interior moisture away from cold steel: airtightness at the sheathing plane, insulation outboard of the structure, and careful membrane transitions at slab edges and roof junctions.
Commercial assemblies carry engineering obligations beyond this general documentation — coordinate the specifics with your design professional of record.
Membrane or taped sheathing at the exterior face of the frame, transitions detailed at every junction.
Insulation outboard of the steel — the layer that makes the thermal picture work.
WRB and ventilated cavity behind the cladding system.
Slab edges, parapets, and curtain-wall transitions — where commercial envelopes are won and lost.
Bring the typical bays to the desk — we'll walk the membranes and tapes per junction.
Ask the Spec Desk