OSB3 Board Explained: Uses, Sizes & How to Buy

OSB3 is one of the most cost-effective structural boards on site. This guide covers what OSB3 is, where to use it, the sizes we stock, and how to buy it by the pallet.

What is OSB3?

OSB (oriented strand board) is an engineered panel made from compressed wood strands bonded with resin. The "3" grade is load-bearing and rated for use in humid conditions, which makes it far more versatile than basic OSB2. It is strong, consistent and cheaper than most plywood — the reason it is so widely used in construction. Browse the OSB3 range.

Common uses

OSB3 is used for roof decking, floor decking, wall sheathing, site hoarding, timber-frame construction, packaging and temporary structures. Tongue-and-groove (T&G) versions make tight, squeak-free floor and roof decks — see our 18mm OSB3 T&G board.

Sizes & thicknesses

We stock OSB3 in 11mm, 15mm and 18mm. Standard sheets are 8x4 (1220 x 2440mm), with 15mm available in 1197 x 2397mm and an 18mm 8x2 T&G board for flooring. Thicker boards span further between joists and feel more solid underfoot.

OSB3 vs plywood

OSB3 is usually the cheaper choice and performs well structurally, but plywood is lighter for its strength, holds screws better at the edges and gives a cleaner face. For hidden structural decking and sheathing, OSB3 is hard to beat on value; for visible or finished work, consider plywood.

Buying OSB3 by the pallet

All Sheets supplies OSB3 at trade prices by the pallet, delivered across London and the South East — no account application needed. View the OSB3 range or contact us for a bulk quote.