“Rainscreen” describes a rain-control approach, not a single cladding product. The visible skin sheds most water, while a cavity, drainage plane and carefully connected flashings manage the water that passes through joints. Selecting a system therefore means deciding how the whole wall will drain, dry, resist pressure and maintain its critical barriers—not simply choosing a panel finish.
Separate the cladding from the water-control system
Open-jointed terracotta is normally the outer layer of a multi-layer wall. It resists wind, impact and weathering and provides the architectural surface, but it should not be described as the sole waterproof layer. Behind it, a clear cavity creates a capillary break and drainage route. The water-resistive barrier, flashings and interfaces return collected water to the exterior.
The support wall or sheathing also carries the continuous air-control layer, while insulation and vapour-control materials are selected for the climate and interior conditions. Brackets and fasteners cross some of these layers, so their structural, thermal and water-management effects must be coordinated. A sound selection keeps each function identifiable on sections and at every transition.
Use categories that describe real cavity behaviour
| System description | How it manages rain | Design emphasis |
|---|---|---|
| Drained and vented | Deflects most rain, accepts limited entry, then drains water and provides openings for local drying | Continuous cavity, reliable flashings, open drainage paths and a durable inner water-control layer |
| Drained and ventilated | Adds deliberate low- and high-level openings to promote greater airflow through the cavity | Inlet and outlet design, insect protection, fire strategy and avoidance of blocked air paths |
| Pressure-moderated or pressure-equalized | Uses vents and compartmentation to reduce pressure differences that can drive rain through outer joints | Airtight backing, sized openings, stiff compartments, sealed boundaries and project-specific verification |
The archived article dated 2 December 2015 divided rainscreens into “simple” and “pressure-equalized” categories. That is a useful introduction but too broad for a specification. Field pressure rarely equalizes perfectly, so many practitioners use “pressure-moderated” for the practical behaviour. The Building Science rain-control overview also stresses that drainage remains fundamental.
Match the strategy to exposure and consequence
Start with project wind and rain exposure: building height, coastal or inland location, topography, surrounding buildings, facade orientation and vulnerable corner zones. Then consider wall geometry. Re-entrant corners, parapets, soffits, balconies, deep reveals and frequent penetrations complicate drainage and compartment boundaries.
Risk is also shaped by what lies behind the cladding. Moisture-sensitive construction, critical interior uses and limited inspection access justify more conservative details and verification. Local code requirements for fire, structure, energy, condensation and materials can govern the assembly. Do not select a lighter strategy solely because annual rainfall is low; wind-driven events and construction tolerances may be more important than an annual total.
Coordinate the barriers and every exit path
Water
Show the drainage plane, shingled laps, sill pans, end dams, flashings, weeps and discharge points. Water must not drain into another assembly or onto unprotected fixings.
Air
Keep the air barrier continuous at floors, roofs, windows, doors and service penetrations. Pressure moderation depends on a substantially tighter backing layer.
Heat and vapour
Model thermal bridges through brackets and rails, maintain insulation continuity and locate vapour-control layers from a project-specific hygrothermal assessment.
Fire and structure
Coordinate cavity barriers, support rails, movement joints and anchors without silently interrupting drainage, ventilation or the structural load path.
At openings, the window or door perimeter must connect to the wall’s air and water layers. At the base, leave a maintainable outlet and protect it from blockage. Sealant may be part of a two-stage joint or interface, but exposed face sealant should not become the undocumented first and only rain defence.
Select the cladding and attachment route together
Large-format terracotta rainscreen panels commonly use clips, rails and purpose-made panel grooves. Mechanical dry-hanging options for smaller facing units follow a different module and load path. Terracotta baguettes create an open screen rather than a planar rain-shedding surface. Each route changes joint openness, cavity access, bracket layout, edge details and replacement procedure.
Compare systems at a consistent boundary: cladding units, subframe, brackets, fasteners, isolators, closures, flashings, engineering, testing and installation labour. Confirm substrate tolerances and adjustment range. A low unit price can be misleading if it requires dense rails, complex closures or extensive site modification.
Define evidence, mock-ups and field quality checks
Ask for current product data and calculations covering the proposed panel, attachment and project loads. Specify laboratory or project testing appropriate to the jurisdiction and risk, including the representative joints, openings and interfaces—not an idealized blank wall. For pressure-moderated designs, establish compartment size, vent area, backing airtightness and the method used to verify them.
Use a visual mock-up to approve colour range, joints, corners and support visibility. A performance mock-up can establish water paths and expose interface problems before production. During construction, inspect membranes before concealment, test air-barrier work where required, keep cavities and weeps clear, verify anchors, and record repairs. Legacy performance, environmental, market or certification figures from the 2015 page require confirmation in current project documents.
Issue a decision brief before requesting prices
Provide elevations and full-size details, wall build-up, exposure data, design loads, panel module, attachment scope, substrate, barrier responsibilities, fire strategy, test criteria, samples, mock-ups, quantities and programme. State whether bidders may propose alternatives and require a marked comparison of cavity behaviour, interfaces and exclusions.
Explore terracotta cladding routes, compare built work in the project gallery, and review practical next steps on the contact page.