Retrofitting traditional stone or brick buildings requires a delicate balance between improving thermal performance and maintaining the structure's integrity. Many traditional walls fail to meet modern insulation standards without compromising their breathability or moisture management. The Retro EcoWall® system, developed by Ecological Building Systems, offers a comprehensive and sustainable solution to this challenge.
Launched at the RIAI Architecture & Building Expo in 2022, Retro EcoWall® uses a blend of innovative materials and techniques to create an internally insulating system that works in harmony with the fabric of the building. The system incorporates Diasen Diathonite Thermactive.037 cork-lime thermal plaster, Gutex Thermoroom wood fibre insulation boards, Lime Green Solo finishing plaster, and breathable natural paint finishes from Auro. This combination not only provides insulation but is also airtight, breathable and effectively manages moisture in the wall to prevent issues such as condensation and mould - which is common when traditional walls are sealed with inappropriate impervious synthetic materials.
About Retro EcoWall®
Prior to the internal application of Retro EcoWall®, it is important to consider and protect exposed external masonry walls from wind driven rain and moisture. This can be achieved by applying a suitable lime plaster, thermal insulation, such as Diasen Diathonite Evolution, external breathable paint, or a breathable transparent surface treatment such as Diasen BKK Eco to the external brick or stone. It’s also important to have effective drainage at ground level, with gutters, downpipes and lime pointing effective and well maintained.
The Retro EcoWall® system has also been verified using WUFI hygrothermal modelling on numerous projects by independent consultants and Ecological Building Systems.
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 details the key system components and performance information for Retro EcoWall®.
Retro EcoWall® provides the thermal benefit needed to meet U-value targets and provides effective moisture management. It does this by combining capillary active Diasen Diathonite cork lime thermal plaster with a high performance vapour open Gutex wood fibre insulation board. With a breathable one-coat lime finishing plaster and plastic free natural paints on top, the entire system is ideally suited to the thermal and moisture requirements of a traditional building.
Key Benefits
Complete Specification Solution
Includes insulating cork-lime plaster and wood fibre boards.
Breatheable System
Prevents condensation, mould, and deterioration.
Low-Carbon Materials
With Environmental Product Declarations (EPDs).
Improved U-values
With minimal space loss (e.g., U-value of 0.35 W/m²K for stone walls).
Quick Installation
Reduces time and costs compared to traditional retrofitting methods.
Hygrothermal Performance
Verified using WUFI modelling to ensure moisture management and durability.
Retro EcoWall® is compatible with solid brick or stone walls
Diason Diathonite Thermactive .037 lime and cork based insulating plaster
Gutex Thermoroom Adhesive mortar
Gutex Thermoroom natural wood fibre internal wall insulation board
Lime Green Solo smooth finishing plaster with embedded reinforcing mesh
Auro Natural Breathable Paint
Brick Walls
High-performance thermal insulation for solid brick walls that promotes breathability in the walls and protects against condensation, mould and building deterioration. Manages moisture, regulates humidity, eliminates mould and minimises heat-loss; especially in older or historic buildings or newer buildings suffering condensation and mould problems.
- Diasen Diathonite Thermactive.037 lime and cork based insulating plaster. Used as a leveling plaster.
- Gutex Thermoroom adhesive mortar. Secures the boards to the levelled wall.
- Gutex Thermoroom natural wood fibre internal wall insulation board
- Lime Green Solo smooth finishing plaster with embedded reinforcing mesh
- Auro Natural Breathable Paint
| Wall Type | Diathonite Thermactive.037 Levelling Plaster (mm) | Wood Fibre Thickness (mm) | U-value (W/m²K) |
|---|---|---|---|
220mm | -- | -- | 2.19* |
220mm | 20mm | 40 | 0.49 |
220mm | 20mm | 60 | 0.39 |
220mm | 20mm | 80 | 0.32 |
220mm | 20mm | 100 | 0.28 |
Diason Diathonite Thermactive .037 lime and cork based insulating plaster
Thermoroom Adhesive mortar
Gutex Thermoroom natural wood fibre internal wall insulation board
Lime Green Solo smooth finishing plaster with embedded reinforcing mesh
Auro Natural Breathable Paint
Stone Walls
High-performance thermal insulation for solid stone walls that promotes breathability in the walls and protects against condensation, mould and building deterioration. Manages moisture, regulates humidity, eliminates mould and minimises heat-loss; especially in older or historic buildings or newer buildings suffering condensation and mould problems.
- Diasen Diathonite Thermactive.037 lime and cork based insulating plaster. Used as a leveling plaster.
- Gutex Thermoroom adhesive mortar. Secures the boards to the levelled wall.
- Gutex Thermoroom natural wood fibre internal wall insulation board
- Lime Green Solo smooth finishing plaster with embedded reinforcing mesh
- Auro Natural Breathable Paint
| Wall Type | Diathonite Thermactive.037 Levelling Plaster (mm) | Wood Fibre Thickness (mm) | U-value (W/m²K) |
|---|---|---|---|
500mm | -- | -- | 2.38* |
500mm | 30mm | 40 | 0.44 |
500mm | 30mm | 60 | 0.35 |
500mm | 30mm | 80 | 0.30 |
500mm | 30mm | 100 | 0.26 |
