STEICO Internal
STEICO Internal is a rigid wood fibre insulation board designed for internal wall insulation in masonry and mineral wall constructions. Manufactured from natural wood fibres, it improves thermal performance while remaining vapour open and moisture regulating, helping to support healthy indoor environments.
With a declared thermal conductivity of λ = 0.038 W/mK, STEICO Internal provides an effective insulation solution where external insulation is not possible or where façades must be retained. The boards are suitable for renovation projects and can be used with compatible vapour-open lime and mineral plaster systems.
Technical Data
| Property | Value |
|---|---|
| Product Type | Internal Wood Fibre Insulation Board |
| Material | Wood Fibre |
| Board Size | 1200 × 380 mm |
| Thicknesses Available | 40mm, 60mm |
| Thermal Conductivity (λD) | 0.038 W/mK |
| Vapour Diffusion Resistance (μ) | 5 |
| Density | Approx. 160 kg/m³ |
| Specific Heat Capacity | 2100 J/kgK |
| Fire Classification | Euroclass E |
| Compressive Strength | 50 kPa |
| Tensile Strength Perpendicular to Face | ≥ 2.5 kPa |
| sd Value | 0.20m (40mm), 0.30m (60mm) |
Key Benefits
High Thermal Performance
With a declared thermal conductivity of λ = 0.038 W/mK, STEICO Internal delivers effective insulation performance while maintaining relatively slim wall build-ups.
Vapour Open Construction
The board is vapour open, supporting moisture movement through the wall construction and helping to maintain a healthy indoor climate.
Moisture Regulating
STEICO Internal can absorb, temporarily store, and release moisture, supporting balanced indoor humidity levels and moisture management within the building fabric.
Suitable for Renovation Projects
Ideal where external insulation is not feasible, including masonry buildings, traditional constructions, and projects where the external appearance must be retained.
Compatible with Breathable Finishes
Designed for use with compatible vapour-open plaster systems, including lime-based and mineral plasters.
Natural & Sustainable
Manufactured from natural wood fibres sourced from sustainably managed forests and produced using the wood's own lignin as a natural binding agent.
Typical Applications
| Application | Suitability |
| Internal Wall Insulation | ✓ |
| Masonry Walls | ✓ |
| Solid Wall Renovation | ✓ |
| Traditional Buildings | ✓ |
| Mineral Substrates | ✓ |
| Breathable Retrofit Systems | ✓ |
| Rooms Where External Insulation Is Not Possible | ✓ |
Why Use STEICO Internal?
Internal wall insulation is often the preferred solution where external façades must be retained or where only individual rooms or dwellings are being upgraded.
STEICO Internal combines effective thermal insulation with vapour-open construction and moisture-regulating properties, making it suitable for use within breathable wall systems. When combined with compatible lime or mineral plasters, it supports moisture management while improving internal comfort and energy efficiency.
Installation Overview
1. Surface Preparation
Substrates should be clean, stable, and suitable for receiving the insulation system.
2. Board Fixing
Install boards using an approved fixing method and compatible adhesive system.
3. Reinforcement Layer
Apply a suitable reinforcement layer and mesh in accordance with the system specification.
4. Plaster Finish
Finish with a compatible vapour-open lime or mineral plaster system.
5. Decoration
Decorate with suitable breathable finishes such as mineral paints, silicate paints, limewash, or other compatible coatings.
