Achieving effective thermal insulation without compromising the breathability of walls is a key consideration in sustainable building projects. Diasen Diathonite offers a natural and highly effective solution for both internal and external wall insulation. This innovative plaster system enhances thermal performance by reducing heat loss while maintaining the building’s breathability - crucial for managing moisture and ensuring a healthy indoor climate.
The plaster, made from a combination of cork, lime and natural materials, creates a capillary active layer that provides superior insulation while allowing the walls to breathe. This helps maintain a balanced indoor environment, ensuring that heat is retained in winter and kept out in summer, which is essential for improving energy efficiency. While the primary benefit of Diathonite is its thermal insulation, it also helps regulate moisture, preventing issues like condensation and mould growth by allowing moisture to escape without being trapped.
After any existing moisture issues such as leaks have been rectified, Diathonite and Argatherm can help to regulate condensation and resist mould growth. When applied internally, Diathonite provides a warm and comfortable living space while managing humidity. Externally, it acts as an insulating layer and protects the building from temperature fluctuations, offering a sustainable solution for renovation projects.
Applied over Diathonite as a finishing skim coat, Diasen Argatherm creates a highly breathable and mould-resistant finish. It can be hand applied or sprayed with no other surface preparation required and gives a smooth to semi-smooth finish which can be painted or followed by Argacem Ultrafine for an ultra-smooth finish. Combined with a natural paint, Argathem provides a high-quality finish internally or externally.
About Diasen Diathonite
Diasen Diathonite offers an innovative, natural solution for wall insulation, perfect for both internal and external applications. Its unique cork and lime-based composition ensures it provides excellent thermal comfort while retaining the natural breathability of the building fabric.
Internally, Diathonite prevents heat loss, making it ideal for rooms where energy efficiency is a priority. Finished with Argatherm and a natural paint, its moisture-regulating properties and thermal benefits prevent condensation, keeping the walls dry and maintaining a comfortable indoor temperature. Externally, the system provides an insulating layer that protects the building from the effects of temperature fluctuations and moisture ingress, making it a great solution for renovations.
With its high thermal performance, Diathonite is a highly effective solution for modern insulation standards, reducing the need for synthetic, non-breathable materials. Its ecological benefits ensure it is a sustainable option that minimises a building's carbon footprint while maintaining a healthy, comfortable indoor environment.
As with any Internal Wall Insulation system, the wall must have any sources of water infiltration from ground sources, poor pointing, water leaks or poorly maintained gutters/pipes etc made good before installing the insulation. Refer to our guidance document: “How to prepare walls for Internal Wall Insulation” for full details.
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This system guide provides key information and performance data for the Diasen product range.
Diasen Diathonite provides an environmentally friendly and effective solution for both internal and external wall insulation. Its natural cork and lime-based composition ensures superior thermal insulation, improving energy efficiency and comfort. While its breathable, capillary active nature helps regulate moisture, the system’s primary benefit is its ability to reduce heat loss and enhance the building’s overall thermal performance. Suitable for renovation projects, Diathonite offers long-term comfort and sustainability while maintaining the integrity of the building's fabric.
Key Benefits
Highly effective insulation
Thermal insulation that improves energy efficiency and comfort.
Breathable composition
Prevents condensation and mould while regulating moisture.
All applications
Ideal for both internal and external wall applications.
Natural
Cork and lime-based plaster that uses eco-friendly materials.
Sustainable
By providing an alternative to non-breathable insulation, it enhances sustainability.
Renovations and Retrofits
Suitable for renovations, enhancing building performance.
Diathonite can be installed internally or externally
Diasen Diathionite Thermactive .037 Lime and cork based insulating plaster
Diasen Argacem Ultrafine Breathable lime-based finishing plaster skim coat for a very smooth finish on top of Argatherm
Auro Natural Breathable Paint
Internal Wall Insulation
Diasen Diathonite, finished with Diasen Argatherm and a breathable paint, is an excellent solution for internal wall insulation, especially in areas exposed to high levels of humidity or moisture. This breathable plaster helps prevent heat loss while regulating moisture, reducing the risk of condensation and the long-term damage caused by damp. Its breathability and capillary active properties allow the wall to breathe while also ensuring temperature stability, creating a comfortable, dry living environment. Ideal for renovations, Diathonite enhances the thermal insulation of walls and improves energy efficiency, while also stabilising moisture and temperature.
- Diasen Diathionite Thermactive .037 Lime and cork based insulating plaster
- Diasen Argacem Ultrafine Breathable lime-based finishing plaster skim coat for a very smooth finish on top of Argatherm
- Auro Natural Breathable Paint
Diathonite Regularisation Restoration plaster and salt barrier
Diathonite Evolution Lime and cork insulating plaster
Diasen Watstop Epoxy cement-based waterproof tanking plaster
Diasen Argatherm Lime-based finishing plaster
Auro Natural Breathable Paint
External Wall Insulation
When used for external wall insulation, Diasen Diathonite offers a durable solution for both moisture management and thermal performance. It provides a breathable, insulating layer that protects the building from extremes of temperature while regulating the internal temperature. This is particularly beneficial in areas prone to rain or high humidity. By improving the thermal insulation of external walls, Diathonite reduces energy consumption and stabilises the internal climate, creating a more comfortable environment. Finished with a coat of Diasen Argatherm, a coat of Watstop and a natural breathable paint, this system offers long-lasting protection against weathering and moisture damage.
- Diathonite Regularisation Restoration plaster and salt barrier
- Diathonite Evolution Lime and cork insulating plaster
- Diasen Watstop Epoxy cement-based waterproof tanking plaster
- Diasen Argatherm Lime-based finishing plaster
- Auro Natural Breathable Paint
Wall Type | Thickness of Application (mm) | Diathonite Evolution U-Value (W/m²K) | Diathonite Thermactive U-Value (W/m²K) |
|---|---|---|---|
| 220mm brick | Uninsulated wall* | 2.19 | 2.19 |
20 | 1.07 | 0.97 | |
30 | 0.86 | 0.77 | |
40 | 0.72 | 0.63 | |
50 | 0.62 | 0.54 | |
60 | 0.55 | 0.47 | |
70 | 0.49 | 0.42 | |
80 | 0.44 | 0.37 | |
90 | 0.40 | 0.34 | |
100 | 0.36 | 0.31 | |
110 | 0.34 | 0.28 | |
120 | 0.31 | 0.26 |
Wall Type | Thickness of Application (mm) | Diathonite Evolution U-Value (W/m²K) | Diathonite Thermactive U-Value (W/m²K) |
|---|---|---|---|
| 500mm stone | Uninsulated wall* | 2.38 | 2.38 |
20 | 1.11 | 1.00 | |
30 | 0.89 | 0.79 | |
40 | 0.74 | 0.65 | |
50 | 0.64 | 0.55 | |
60 | 0.56 | 0.48 | |
70 | 0.49 | 0.42 | |
80 | 0.44 | 0.38 | |
90 | 0.40 | 0.34 | |
100 | 0.37 | 0.31 | |
110 | 0.34 | 0.29 | |
120 | 0.32 | 0.27 |
* Adopting best practice, the values given for existing uninsulated stone and brick walls are derived from EN ISO 10456: 2007. U-values can vary depending on stone or brick type.
Above based on Argatherm applied at a thickness of 4mm (2 coats of 2mm).
