Glazed exterior terracotta panels combine a fired-clay profile with a glaze selected for the architectural surface. Exterior specification must connect colour and gloss to the exact panel, support system, exposure, joints, runoff, production controls and current evidence. A digital colour or archived photograph can inspire a brief, but only current samples and documents can approve it.
Identify the exact exterior panel
Request the current product code and section drawing. Record face dimensions, actual thickness, internal cells and webs, fixing grooves, unit mass, edge condition, orientation, tolerances and cut limits. Confirm whether the archived FY code remains active, has a successor or is only a historic image reference.
State the building location and height, facade zones, substrate and intended support arrangement. Identify who designs clips, rails, brackets and anchors, and who reviews glaze compatibility with the profile. Product development and system engineering should have distinct owners and coordinated deadlines.
The panel must be compatible with proposed clips and rails. A glaze shown on one face size or profile should not be assumed available on another. Tie panel, glaze, drawing revision, quotation, samples and evidence together before architectural approval begins.
Turn colour intent into a fired sample process
Describe hue, value, saturation, opacity, gloss and permitted variation. State whether the facade should read as a uniform field, controlled blend, gradient or deliberate pattern. Reference colour systems and digital images can communicate direction, but the approved finish should be based on physical fired samples.
For a custom glaze, define laboratory or factory trials, sample count, full-panel stage, measurement method where used, approval ownership, minimum quantity, development cost and programme. Record what happens if the target cannot be achieved on the selected body or profile. “Any nuance” should not become a contractual promise.
Approve variation and lighting at full scale
Sample range
Review several pieces showing proposed light, middle and dark limits, gloss, coverage and surface character.
Full panel
Assess distribution, bow, relief, edges and the relationship between glaze and exposed clay.
Mock-up
Include multiple panels, actual joints, corners, supports and adjacent materials under relevant project light.
Control set
Retain labelled approved limits with product, glaze, batch, date and decision references.
Gloss and relief can change perceived colour with sun angle, shade and night lighting. Review the elevation at intended viewing distance. Agree blending or location rules, inspection lighting and how production units outside the approved range will be handled.
Coordinate joints, runoff and soiling
Show module, orientation, joint width and colour, corners, soffits, openings and cut edges. Dark open joints may strengthen the grid, while closely toned backing can create a quieter field. Confirm how glaze terminates at edges and whether exposed body colour supports the design.
Detail flashings, drips, slopes and drainage so concentrated runoff does not create avoidable streaks. Consider ledges, dust, salts or other site deposits and safe cleaning access. The rainscreen cavity and backup wall manage water as part of the system; the glazed face should not be called waterproof by itself.
Verify product and wall-system evidence
Map each specification requirement to current evidence. Product questions may include dimensions, absorption, freeze–thaw exposure, strength, impact, glaze behaviour or fire classification. Assembly questions may include structural calculations, anchors, water management, cavity barriers and other project criteria.
Check method, report date, specimen identity, dimensions, glaze, support and scope. A result for an unglazed or different profile needs a documented basis. Review the terracotta rainscreen system for orientation, subject to project engineering and authority acceptance.
Control production and site handling
Connect the approved control set to product, body, glaze route, batch, inspection record, crate and elevation zone. Define checks for dimensions, bow, twist, edge condition, glaze coverage, colour and gloss. Changes to body, firing, glaze, profile or hardware require documented review.
Protect faces and edges during packing, transport, storage and installation. Set inspection lighting and cleaning trials. Do not use abrasive tools or chemicals based on a generic resistance claim; obtain a finish-specific approved method and test it on a control sample.
Release a traceable exterior finish package
Before ordering, align elevations, panel and glaze codes, drawings, orientation, acceptable range, special pieces, support scope, evidence, mock-up record, quantities, spares, packing and programme. Record assumptions and exclusions. Include installed locations and batch data in handover.
Agree an inspection and maintenance plan for joints, runoff paths, panels, supports and interfaces. Define how chips, cracks, glaze damage, staining or loose units will be diagnosed before repair. Store labelled spares and the approved cleaning trial so future work does not rely on visual guesswork.
Use the finish approval guide and examples in the project gallery for development, not as proof that an archived glaze remains available or suitable.