STEICO Special Dry
STEICO Special Dry is a rigid wood fibre insulation board designed for use as a sarking board and external sheathing board in breathable roof and wall constructions. Manufactured using natural wood fibres, it combines thermal insulation, wind protection, and temporary weather protection within a single vapour-open board.
Its tongue-and-groove profile helps create a windtight outer layer while maintaining vapour permeability, making it suitable for timber frame walls, pitched roofs, and renovation projects where breathable construction is required.
Technical Data
| Property | Value |
|---|---|
| Product Type | Wood Fibre Sarking & Sheathing Board |
| Material | Wood Fibre |
| Thermal Conductivity (λD) | 0.038 W/mK |
| Density | Approx. 140 kg/m³ |
| Vapour Diffusion Resistance (μ) | 5 |
| Specific Heat Capacity | 2100 J/kgK |
| Fire Classification | Euroclass E |
| Compressive Strength | 100 kPa |
| Tensile Strength Perpendicular to Face | ≥ 10 kPa |
| Thicknesses Available | 60mm–200mm |
| Standard | EN 13171 |
Key Benefits
Excellent Thermal Performance
With a declared thermal conductivity of λ = 0.038 W/mK, STEICO Special Dry provides high levels of thermal insulation while maintaining a breathable construction.
Vapour Open Construction
The diffusion-open structure allows moisture vapour to pass through the building envelope, supporting healthy and durable wall and roof assemblies.
Windtight & Weather Resistant
The tongue-and-groove profile helps reduce unwanted air movement through the construction while providing temporary weather protection during installation.
Suitable for Roof & Wall Applications
Designed for use as:
- A sarking board above rafters
- External sheathing for timber frame construction
- External insulation within breathable wall systems
Summer Heat Protection
The wood fibre structure and high specific heat capacity help slow heat transfer through the building fabric during warmer periods.
Sustainable & Renewable
Manufactured from wood sourced from responsibly managed forests and produced using renewable raw materials.
Typical Applications
| Application | Suitability |
| Sarking Board for Pitched Roofs | ✓ |
| Above-Rafter Insulation Systems | ✓ |
| External Timber Frame Sheathing | ✓ |
| Breathable Roof Constructions | ✓ |
| Breathable Wall Constructions | ✓ |
| New Build Projects | ✓ |
| Renovation Projects | ✓ |
Why Use STEICO Special Dry?
STEICO Special Dry combines thermal insulation, windtightness, and weather protection within a single board, helping simplify wall and roof build-ups while maintaining vapour permeability.
Its lower density compared to STEICO Universal Dry allows it to provide higher insulation performance while remaining suitable for external roof and wall applications where breathable construction is required.
Installation Overview
1. Preparation
Ensure the supporting structure is level, dry, and suitable for installation.
2. Board Installation
Install boards with tight tongue-and-groove joints in accordance with STEICO installation guidance.
3. Weather Protection
Boards provide temporary weather protection during construction when installed correctly.
4. Detailing
Seal junctions and penetrations using compatible tapes and membranes where required.
5. Final Finish
Complete the roof or wall build-up with the specified roof covering, façade system, or external finish.
