The product
A mid-texture clay finish at 4 to 5 mm. More aggregate movement than Smooth, more tonal variation, still an even plane at a distance. The most widely specified finish in the range.
Where it is used
- Interior walls and ceilings in controlled interior environments
- Bathrooms and kitchens, outside wet zones and away from cooking splash zones
Substrates
- Refer to the Clayworks Design Details data sheet for full substrate guidance
Application data
Coverage, thickness, mix and cure, as declared by the manufacturer. Site conditions in the Gulf sit at the top of most of these ranges — allow for it in the programme.
| Supply | 25 kg bags |
|---|---|
| Applied thickness | Top coat 4 – 5 mm |
| Coverage | 2.6 m² nominal per 25 kg bag |
| Drying | Approximately 51 – 72 hours |
| Colours | 89 standard colours plus custom matching |
| Warranty | 10 years manufacturer's warranty, subject to correct detailing, application and maintenance |
| Life expectancy | 60 years, subject to correct detailing, application and maintenance |
| Application requirement | Standard finishes: professional application. Custom finishes: specialist application. |
Performance data
Every figure below is reproduced from the manufacturer's own technical data sheet, with the test standard it was measured against. The sheet itself is in the download section.
| Property | Result | Standard |
|---|---|---|
| Reaction to fire | Euroclass A1; also tested to ASTM E84 | EN 13501, EN 15824, ASTM E84 |
| Noise reduction coefficient | 0.15 – 0.25 NRC depending on backing board | BS EN ISO 354 |
| Applied density | 1682 kg/m³ — 10.1 kg/m² at 4–5 mm | Clayworks data sheet |
| Impact | Impact diameter < 15 mm | BS EN 520 |
| Thermal conductivity | 0.84 W/mK | Clayworks data sheet |
| Moisture buffer value | 1.4 | Clayworks data sheet |
| Light reflectance value | 20.0 (purple) to 49.0 (pink) | BS 8493:2008 + A1:2010 |
| Embodied carbon | 0.048 kg CO₂e/kg | LCA stages A1–A3 |
| VOC | Trace VOCs; mineral and inert. Emission testing published by Clayworks | Eurofins, EN 16516 / ISO 16000-6 |
| Breathability | Hygroscopic; buffers short-term humidity swings. The 40–60% figure is the manufacturer's, measured under test conditions — a finish moderates a room, it does not hold it at a set value | Clayworks data sheet, EN ISO 12571 |
| End of life | Reusable, or returnable to earth once dried | Clayworks data sheet |
Where not to use it
The limits are as much a part of the specification as the performance. Everything here is stated on the manufacturer's data sheet.
- Not for wet or shower areas
- Not for areas in direct contact with oils and fats, such as cooking splash zones
- Not suitable for floors, standard doors, or elements subject to frequent movement
- Custom finishes must be installed by an approved applicator
Clay plaster: Clayworks Interior Demi-Rustic Finish in colour [ref], top coat 4–5 mm over the primed substrate scheduled, to the approved sample panel. Reaction to fire Euroclass A1 to EN 13501 and EN 15824. Substrate preparation and junctions to the Clayworks Design Details data sheet. Applied by a Clayworks Approved Applicator.
Square brackets mark the choices that belong to the project. Send us the finishes schedule and we will return the clause completed, with the sample and mock-up programme against it.
Documents
Every document is the manufacturer's own, reproduced in full and unaltered under our cover. Free to download, no form.
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Interior Demi Rustic Finish Clay plaster · Technical data sheet · 5 pp · 1.1 MBDownload (PDF, 1.1 MB)
The rest of the clay plaster range
Technical support for the design team
We supply the material and we apply it, so the specification and the workmanship sit with one party. Send a finishes schedule, an elevation or a mood board and we will come back with the system, the build-up, the sample programme and a completed clause.