Line-surface terracotta panels should be selected as a controlled combination of relief, direction, colour range, module and joint—not from a close photograph alone.
This guide uses the complete 2020 archive images to show how a fine linear or ribbed surface changes with light, orientation and viewing distance. It also sets out the samples, drawings, system interfaces and project evidence needed before a surface is approved for fabrication or installation.
Read the relief before choosing a product
Begin by distinguishing fine striations, pronounced ribs, regular grooves and intentionally irregular relief. Ask for a current profile drawing and a physical sample rather than relying on a finish name: two products called “linear” can produce very different shadow, edge and cleaning conditions. Record which way the lines run on the panel, the intended installation orientation and the face that is to remain exposed.
Review the sample at the expected facade distance as well as close up. Fine lines may merge into a quiet tone from far away, while deeper or irregular ridges remain legible and cast stronger shadows. A close image is useful for texture identification but cannot establish colour under project lighting, surface roughness, tolerances, strength, weathering or suitability for a particular exposure.
Direction and light change the reading
Line direction establishes a visual axis. Vertical lines can reinforce height; horizontal lines can strengthen coursing and apparent length; changes of direction can mark bays, soffits or returns. That effect depends on the panel module and surrounding joints, so the elevation drawing should show both the relief direction and every unit boundary.
Raking sun, overcast sky, artificial lighting, wetting and the observer’s position can all alter the balance of highlight and shadow. Use a full-size external visual mock-up at representative orientations and observe it at planned approach routes and useful times of day. Agree the acceptable appearance in ordinary light; do not approve a directional finish from a single studio image or assume it will eliminate glare or “light pollution.”
Module and joints create a second pattern
A line finish does not conceal the panel grid. Panel length and height, joint width and colour, groove termination, stagger or stack bond, corner treatment and opening alignment can compete with or reinforce the surface direction. Test the whole elevation hierarchy: fine relief at close range, unit joints at mid-range and primary grids, openings and building massing at long range.
Coordinate the visible grid with the support concept and enclosure layers. Establish design actions, spans, fixed and movement points, bracket/rail logic, substrate tolerances, cavity, insulation, membranes, flashings, drainage and ventilation, cavity barriers where required, perimeter fire containment and interfaces with windows, roofs and bases. Product imagery is not a substitute for project engineering or configuration-matched testing.
Resolve edges, corners and openings early
Returns and changes of plane
Choose a manufacturer-confirmed return, corner unit, cut-and-return detail or another engineered solution. Review line continuity, exposed ends, colour at cut faces, joint position, water shedding and replacement access.
Windows and penetrations
Set out jambs, heads, sills, flashings, seals and cavity terminations with the relief and panel grid. Confirm how drainage remains continuous and how installation tolerances are absorbed.
Cutting and drilled work
Use released fabrication instructions, minimum edge conditions and approved equipment. Recheck support, cell exposure and load path around every cut; “cut at will” is not a safe specification.
Base, parapet and soffit
Coordinate runoff, ventilation, insect control where required, staining risk, edge protection and access. Do not allow the finish concept to interrupt required flashings or fire/water interfaces.
Approve a batch range, not one perfect piece
Fired clay appearance can vary with raw material, forming, surface tooling and production. Define an approved control sample and an agreed range showing acceptable colour, tone, relief and surface character across the intended production. Label samples with current product identity, finish, colour, production reference and approval date; keep them available for factory and site comparison.
Plan panel distribution before installation when the design calls for controlled blending. Establish inspection lighting, viewing distance, acceptance responsibility, treatment of isolated outliers and rules for replacement stock. “Consistent colour” should become an agreed range and inspection method—not an absolute promise inferred from one photograph.
| Product identity | Current product/profile and finish codes, section and face orientation, permitted dimensions, tolerances, edge/cut rules, weight and packaging identification. |
|---|---|
| Appearance | Labelled colour and relief samples, approved range, panel-joint mock-up and project viewing/lighting criteria. |
| Structure | Project calculations and/or tests matching panel section, span, supports, anchors, design actions, movement and substrate conditions. |
| Enclosure | Coordinated cavity, membrane, insulation, drainage/ventilation, opening, transition and seal details; air/water evidence where specified. |
| Fire and durability | Applicable material and assembly evidence, cavity/perimeter fire-stopping interfaces, exposure-specific durability data and a documented change-control process. |
| Handover | Approved shop drawings, batch records, inspection reports, cleaning trials, maintenance/access plan, spare strategy and replacement procedure. |
What the 20 January 2020 archive did—and did not—record
The original post is retained as a dated source, not rewritten into a current technical promise. It recorded no item number, purchasable size, tolerance, fixing detail, test report or project identity. Its numeric and performance language therefore needs current confirmation before reuse.
| Clay, extrusion and 1200°C | The 2020 article described natural clay, extrusion and firing at 1200°C. This is a dated marketing description, not a current product-specific manufacturing specification or acceptance temperature. |
|---|---|
| Cavity / “porous” form | The article referred broadly to a cavity structure without a section drawing. Confirm the actual current panel profile, cells, supports and cut-edge treatment; do not infer internal geometry from the photographs. |
| Beige, regular or irregular lines | The archive images support examples of warm beige irregular relief and darker installed/production panels. They do not define the current colour or finish range. |
| Environmental and radiation claims | “Environmentally friendly,” “without radiation” and “no light pollution” were unquantified. Use current declarations, test evidence and project assessment against the applicable criteria instead. |
| Large-area colour consistency | No range, metric, batch record or acceptance method was provided. Approve representative samples and a production/installation inspection plan. |
| Can be cut at will | This broad phrase is withdrawn as a design instruction. Only manufacturer-approved fabrication tied to current profile, edge/support limits and project engineering should be used. |
Plan cleaning, inspection and replacement
Relief changes how dust, runoff and local deposits appear and how tools contact the face. Trial the proposed water, brush, detergent and pressure on an approved spare or mock-up; follow current manufacturer guidance and avoid unapproved acids, abrasives or concentrated pressure. Coordinate safe access, runoff control and protection of joints, membranes and adjacent finishes.
At handover, record the approved appearance range, panel locations where useful, inspection frequency, cleaning method, damage criteria and replacement sequence. Keep traceable spares or a re-order strategy. A replacement may match the product code yet still require range review beside weathered work.
- building location, use, height, exposure and applicable performance criteria;
- elevations, grids, line direction, target colour/relief and viewing priorities;
- panel module, corners, returns, openings, soffits, bases and planned cuts;
- substrate, cavity/enclosure build-up, design actions, movement and fire interfaces;
- sample, mock-up, test, inspection and acceptance requirements; and
- programme, packing, access, cleaning, spare and replacement strategy.
Review the current system context on Terracotta Rainscreen, compare built visual references in the Architectural Gallery, and use the technical downloads only after confirming their date and product applicability.
Develop a line-surface panel brief
Share the elevations, desired line direction and relief, target colour range, panel grid and edge conditions, substrate/system concept, project actions, enclosure/fire interfaces, evidence requirements and mock-up plan. Current availability, final engineering, approvals, installation and compliance remain project-specific.