Tongue and Groove OSB3 Flooring Boards

Tongue and Groove OSB3 Flooring BoardsTongue and groove OSB3 flooring boards provide a structural, load bearing sheet solution for subfloors, loft boarding, roofing decks and wall sheathing. The interlocking T&G profile creates a tight, level surface between sheets, and factory sealed edges help control moisture ingress. Available in 18mm thickness at 600mm x 2440mm. Specifications Material Oriented strand board (OSB) Grade OSB3 structural use in humid conditions Profile Tongue and groove

Tongue and groove OSB3 flooring boards provide a structural, load-bearing sheet solution for subfloors, loft boarding, roofing decks and wall sheathing. The interlocking T&G profile creates a tight, level surface between sheets, and factory-sealed edges help control moisture ingress. Available in 18mm thickness at 600mm x 2440mm.

Specifications

What it's used for

• Subfloor decking on timber joists in new builds and refurbishments
• Loft boarding to create usable storage space over ceiling joists
• Flat roofing decks as a structural sarking layer beneath the waterproof finish
• Wall and ceiling sheathing where a structural panel with moisture resistance is required

Fitting and handling

Allow boards to acclimatise in the installation area for at least 24 hours before laying, particularly in loft or ground-floor subfloor situations where temperature and humidity can vary. Fix through the face into joists at 150mm centres around the perimeter and 300mm centres internally, using ring-shank nails or screws appropriate for the joist depth. Leave a 3mm expansion gap at walls and perimeter edges to allow for seasonal movement.

FAQ

What is the difference between OSB2 and OSB3 flooring boards?

OSB3 is rated for structural use in humid conditions under EN 300, whereas OSB2 is only suitable for dry interior conditions. For subfloors, loft boarding or roofing decks where moisture exposure is possible, OSB3 is the appropriate choice and is widely specified by UK building regulations and warranties.

Can T&G OSB3 be used as a finished floor surface?

OSB3 tongue and groove boards are intended as a structural subfloor rather than a decorative finish. They are designed to receive floor coverings such as carpet, vinyl, ceramic tiles (with suitable adhesive) or engineered flooring. The surface texture is not suitable as a standalone wear layer in occupied spaces.

What joist spacing is 18mm OSB3 rated for?

18mm OSB3 T&G flooring boards are generally suitable for joist centres up to 600mm, which aligns with the 600mm board width so joints always fall on a support. For spans up to 450mm centres the boards perform well under standard domestic loading. Always confirm with your structural requirements and local building control where applicable.

Nottage Timber Merchants hold T&G OSB3 flooring boards in stock at our Bridgend yard, with delivery available throughout South Wales. Browse our full range of subfloor and loft boards for complementary sheet materials, or contact the yard for volume pricing and next-day delivery options across the Bridgend area.