Understanding 18 mm, 25 mm and 30 mm Terracotta Panel Thickness
Three thicknesses are manufactured — 18 mm, 25 mm and 30 mm — and each corresponds to a specific panel family and format range. This article maps thickness to family and explains the project-specific coordination process.
Published · 4 min read
Three panel thicknesses are manufactured: 18 mm, 25 mm and 30 mm. Each thickness is tied to a specific panel family and its own set of formats — thickness is not an independent option that can be requested against any format in the range.
25 mm — Single-Skin Terracotta Panel
The 25 mm thickness applies to the Single-Skin Terracotta Panel, manufactured at 200 × 400 mm and 250 × 500 mm. The internal cross-section is not specified by the verified data currently available and should be checked against an approved drawing.
18 mm — Thin Double-Skin Terracotta Panel
The 18 mm thickness applies to the Thin Double-Skin Terracotta Panel. This family is manufactured in six confirmed formats: 300 × 600 mm, 300 × 900 mm, 300 × 1,000 mm, 400 × 600 mm, 400 × 800 mm and 400 × 1,000 mm. Its internal geometry requires an approved cross-section drawing.
30 mm — Heavy-Duty Double-Skin Terracotta Panel
The 30 mm thickness applies to the Heavy-Duty Double-Skin Terracotta Panel and extends to these confirmed formats: 300 × 600 mm, 300 × 900 mm, 400 × 800 mm, 400 × 1,000 mm, 400 × 1,200 mm, 500 × 1,000 mm and 500 × 1,200 mm. Its internal geometry and performance cannot be assumed from the 18 mm family and require separate approved documentation.
Why thickness and format are linked, not independent
In the verified standard range, changing thickness means selecting a different family. A 400 × 1,000 mm panel exists in both the 18 mm and 30 mm families, while a 250 × 500 mm panel is listed only at 25 mm. Reviewing the full dimension tables before finalising a façade grid avoids specifying a combination that is not part of the standard range.
What thickness does not tell you
Panel thickness is a starting reference for fixing and substructure design, not a substitute for it. Load capacity, deflection behaviour, fixing spacing and anchor selection depend on the specific format, span and project wind load, and must be verified against approved technical documentation. The site publishes one six-colour palette and a custom RAL route; availability for the selected family should be confirmed through the colours and surfaces process.
A quick reference table
The following summary is useful for early design coordination, though the individual product pages should always be the reference used for final drawings:
- 18 mm — Thin Double-Skin family — 6 formats, up to 400 × 1,000 mm.
- 25 mm — Single-Skin family — 2 formats, up to 250 × 500 mm.
- 30 mm — Heavy-Duty Double-Skin family — 7 formats, up to 500 × 1,200 mm.
Note that ordering by thickness does not correspond to ordering by format size: the 18 mm family reaches a larger maximum footprint than the 25 mm family. The reason should not be inferred from the names alone; use the approved cross-section and production documentation for technical decisions.
Common misconceptions worth avoiding
A frequent mistake is to assume that thickness scales directly with format size or structural capacity. The available information does not support that conclusion: thickness alone is not a verified proxy for load capacity. Thickness and standard format are grouped by family, and any requested combination outside the published list must be treated as non-standard and assessed for technical feasibility.
Confirming thickness for drawings and schedules
When thickness is entered into a door/window/cladding schedule or a BIM model, it should be cross-checked against the specific format being drawn, not entered as a single project-wide value, since a project may reasonably use more than one panel family across different elevations or building types. Reviewing the technical resources page for the documentation status relevant to the confirmed family is a useful step before schedules are finalised. Where a schedule references a thickness without a matching format, it is worth flagging that as an open item rather than assuming a default, since — as this article has set out — thickness alone does not fully define the product.
It is also worth noting, for anyone coordinating a mixed-material façade schedule, that the millimetre figure quoted for a terracotta panel refers to the panel's own thickness and does not include the substructure, cavity or insulation depth behind it. Overall wall build-up depth is a separate calculation resolved by the façade and structural engineers, using the panel thickness as one input among several rather than as the total assembly figure.
Thickness questions to close before procurement
Ask for the approved product cross-section, individual panel weight, weight per square metre, fixing zones, permissible spans, tolerances and the applicable test documentation for the exact size. Confirm whether the project drawings use one family or several, and label every scheduled dimension in the full format “width × length × thickness mm”. None of these engineering values should be estimated from a photograph, family name or nearby product size.
Where two families share the same face dimension, give each a distinct schedule code that includes thickness and family name. Coordinate that code across elevations, details, bills of quantities and the enquiry form. If a custom intermediate dimension is proposed, keep it marked “subject to technical feasibility and sample approval” until the manufacturer confirms it in writing.
Requesting a non-standard size
Custom dimensions and intermediate sizes may be produced subject to technical feasibility and sample approval. A non-standard request should identify the preferred product family, target thickness, format and quantity so the manufacturer can evaluate it; no tooling or feasibility assumption should be made before that review. Project teams can start with a project enquiry.