Shop our range of OSB boards (Oriented Strand Board) — a strong, cost-effective alternative to plywood, ideal for flooring, roofing, wall sheathing and loft boarding.
What are OSB Boards?
OSB, or Oriented Strand Board, is an engineered wood panel made by compressing layers of wood strands together with a durable resin adhesive. The strands are laid in cross-oriented layers, giving the finished board excellent strength and stability in every direction. It's widely used across construction as a reliable, budget-friendly alternative to plywood, offering similar structural performance at a lower cost.
OSB2, OSB3 and OSB4 - What's the Difference?
Not all OSB is the same, and choosing the right grade matters for your project:
- OSB2 — For general-purpose, dry, non-structural use such as furniture, packaging and internal fittings.
- OSB3 — The most commonly used grade. Moisture-resistant and suitable for structural use in humid conditions, making it the go-to choice for flooring, roofing and wall sheathing.
- OSB4 — A heavy-duty structural grade for demanding load-bearing applications, including flooring, roofing and I-beams, where extra strength is required.
If you're unsure which grade suits your project, our team can help you choose — just get in touch or visit your nearest branch.
Sizes and Thicknesses
OSB boards are typically supplied in the industry-standard sheet size of 2400 x 1200mm, with thicknesses ranging from 9mm up to 18mm depending on the application. Thinner boards (9–11mm) suit lighter, non-structural uses, while 15–18mm boards are better suited to structural flooring, loft boarding and load-bearing applications. Some of our boards also feature tongue and groove edges for a tighter, more secure fit — particularly useful for flooring.
Common Uses for OSB Boards
- Flooring & subflooring — a durable, stable base for domestic and commercial floors
- Loft boarding — creates a stable walking surface and storage area over loft insulation
- Roofing & wall sheathing — provides structural support and weather protection during construction
- Hoarding & site protection — a cost-effective option for site boarding and temporary structures
- Furniture & general construction — suitable for a wide range of DIY and trade projects
Frequently Asked Questions
Is OSB waterproof?
No. OSB3 is moisture-resistant and can withstand humidity and short-term exposure, but it isn't waterproof. For prolonged outdoor use, it should be sealed or protected with a suitable weatherproof coating.
What's the difference between OSB and plywood?
Plywood is generally stronger and more consistent, but OSB offers comparable structural performance at a lower price point, making it a popular choice for cost-conscious flooring, roofing and wall projects.
What thickness of OSB do I need for loft boarding?
18mm OSB is typically recommended for loft boarding, as it provides the strength needed for a stable walking and storage surface across joists.
Can OSB be cut, drilled and painted?
Yes. OSB can be sawn, drilled, sanded and painted like standard timber sheet material, making it easy to work with on site.