How and where to use guide
Sterling OSB Type 3 board 2440mm x 1220mm x 18mm
Typical applications
Sterling OSB Type 3 is engineered specifically for structural use across three primary building elements. The board's load-bearing capability and moisture resistance make it the standard choice for these applications in UK construction.
- Flooring: Use as a structural subfloor base over timber joists or engineered floor systems, providing a stable platform for final floor coverings
- Roof decking: Install as roof sheathing over rafters or truss systems to create a solid base for roofing membranes and tiles
- Wall sheathing: Apply to timber-framed walls as external or internal bracing to provide structural rigidity and weather resistance
Installation and machining
The precision-engineered composition of Sterling OSB Type 3 allows for straightforward on-site handling and cutting. The board machines cleanly, meaning you can cut, notch, and shape it with standard carpentry tools without excessive chipping or splintering. Lay boards with staggered joints to maximise structural performance, and leave a 3mm expansion gap around perimeter edges and between boards to accommodate natural movement. Secure with ring-shank nails or screws at 150mm centres along supports, and 300mm centres in intermediate areas.
- Use a sharp circular saw or handsaw for clean cuts
- Stagger board joints across supports to avoid continuous lines
- Allow for thermal and moisture movement with small gaps at edges
- Ensure full bearing on all supports for load distribution
Environmental performance and durability
Type 3 classification confirms this board is suitable for humid conditions and variable moisture exposure typical of UK construction. The FSC certification guarantees responsible forest sourcing. However, whilst the board tolerates moisture better than Type 2 alternatives, it is not waterproof and should not be left exposed to prolonged standing water or direct weather for extended periods during construction. Protect with temporary coverings on open sites, and allow adequate ventilation in completed structures to prevent moisture accumulation.
- Suitable for humid structural applications and variable weather exposure
- Protect from prolonged water immersion during construction
- Ensure adequate ventilation in completed buildings
- FSC-certified from well-managed forests
On-site handling and storage
Store boards flat or slightly inclined on level ground, raised on bearers to prevent ground contact and allow air circulation underneath. Stack no more than 8-10 boards high to avoid crushing lower boards. Keep boards dry and protected from rain and direct sunlight during storage. On humid or wet sites, allow extra drying time before installation if boards have absorbed moisture. Check boards for damage or delamination before fixing, and reject any with soft spots, significant warping, or edge damage that would compromise structural integrity.
- Stack flat on level bearers, raised from ground
- Limit stack height to prevent compression damage
- Protect from rain and prolonged moisture exposure
- Inspect for damage before installation