A ventilated terracotta facade is a coordinated wall assembly, not a panel with a gap behind it. Its performance depends on continuous control layers, a drainable cavity, structurally verified supports, fire and movement details, and disciplined interfaces. The specification should assign every layer a function, owner and verification method before product data is accepted.
Start with the wall functions, then name the layers
Set project requirements for rain control, air leakage, heat flow, vapour, fire, wind, seismic movement where applicable, impact, acoustics and maintainability. Not every requirement is delivered by the terracotta. The outer panel primarily provides the weather-exposed architectural screen and transfers loads to its support; other layers complete the environmental separation.
Draw the assembly from interior finish to exterior face and mark which material is the primary air, water, thermal and vapour control layer. Show continuity at windows, doors, roofs, bases, corners, movement joints and penetrations. If a material serves more than one function, record the installation conditions that allow it to do so.
Use large-scale three-dimensional details for congested transitions. A clean typical section can hide bracket penetrations, membrane laps, fire-barrier closures and incompatible sequencing that become obvious when trades and installation order are shown together.
Assign a responsibility to every physical layer
| Layer or component | Primary role | Coordination question |
|---|---|---|
| Backing structure or sheathing | Supports anchors and provides a stable base for control layers | Are capacity, tolerances, deflection and anchor zones defined? |
| Air and water-control layer | Limits air flow and drains incidental water | How does it connect at every edge, opening and penetration? |
| Insulation and vapour control | Controls heat flow and moisture risk | Are climate, interior conditions, continuity and drying potential assessed? |
| Brackets, rails and clips | Transfer panel loads and provide adjustment | Who designs fixings, thermal breaks, corrosion protection and movement? |
| Cavity, flashings and barriers | Provide drainage, ventilation where designed, compartmentation and safe discharge | Can water and air reach the intended outlets without bypassing fire details? |
| Terracotta panels and joints | Deflect most rain and create the visible surface | Are profile, span, support engagement, clearances and replacement access coordinated? |
Design drainage and ventilation as visible routes
Assume some rain passes the outer joints. Maintain a clear path down the cavity to flashings and exterior outlets, with end dams and transitions that do not discharge into another assembly. Keep mortar, insulation, membranes, closures and fire barriers from blocking that route. Protect openings from pests where needed without defeating drainage or air movement.
“Ventilated” should describe an intentional airflow strategy, not an unmeasured label. Define low- and high-level openings, compartment boundaries and cavity continuity. Wind pressure, facade orientation and geometry can change local behaviour. Pressure moderation, if required, needs an airtight backing, designed vents and compartments; it should not be assumed from open panel joints alone.
Verify structure, fixings and movement
Establish project wind pressures and suctions, including corners and edges, plus self-weight, seismic demand, impact and maintenance loads where relevant. Trace each action through the panel, clip, rail, bracket, fastener and substrate. Calculations and test evidence must match the proposed profile, span, orientation and support engagement.
Coordinate building drift and differential thermal or moisture movement between fired clay, metalwork and structure. Provide calculated clearances and sliding details without weakening positive retention. Review panel ends, corners, soffits and openings for accidental disengagement. Specify corrosion-resistant, mutually compatible metals and prevent rails from trapping water.
Model heat, air, vapour and fire at interfaces
Brackets and rails can bridge exterior insulation, so assess their effect on the complete wall rather than quoting insulation nominal value. Keep the air barrier continuous around anchors and transitions. Select vapour-control location from climate, interior humidity and assembly drying potential; the WBDG moisture-management guidance reinforces that air, liquid water and vapour must be considered together.
Fire design also belongs to the assembly. Coordinate required classifications, cavity barriers, insulation, membranes, attachments and opening details under the governing code. Do not infer complete-wall performance from a panel-only certificate.
Link each requirement to evidence or a test
Document review
Check current product data, complete test reports, calculations, certificates and laboratory scope against the project schedule.
Visual mock-up
Approve colour range, texture, joints, corners, clips, interfaces and workmanship using production-representative materials.
Performance mock-up
Where required, reproduce representative openings and transitions for agreed structural, air or water testing before full installation.
Field verification
Inspect concealed layers, anchor installation, clip engagement, cavity cleanliness, barriers, flashings and repairs before close-out.
The active NIBS enclosure commissioning guideline treats verification as a process beginning in design and continuing through construction and operations. Match the level of review and testing to the project’s risk and jurisdiction.
Replace the archive data with a current project schedule
The source page dated 15 April 2015 listed panel dimensions, weights, commercial terms, lead time, certificates, technical values and factory-capacity figures, while making broad environmental and performance claims. All are archive entries, not current specifications or production commitments. Verify each applicable item in dated documents for the exact product, factory and order.
Issue a coordinated schedule covering panel codes, dimensions, finishes, quantities, supports, design loads, evidence, samples, mock-ups, tests, inspection hold points, packing, delivery, spares and handover records. Review terracotta rainscreen options and related facade work in the project gallery.