• When fixing to wall studs, nail at 150mm centres along board perimeter and at 300mm centres to intermediate studs
  • Use 3mm (or 0.16 times the board thickness whichever is the greater) wire nails that are at least 50mm long or 2.5 times the thickness of the panel whichever is the greater
  • When fixing sheathing to timber studs, you may meet BS5268 Part 6 Section 6.1 (withdrawn) standard or the current Eurocodes (EN1995-1-1) and all fasteners should be suitably treated to prevent corrosion


  • Allow a 3mm gap between adjacent OSB/3 square edged boards, and a 10mm gap where panels abut rigid upstands.
  • Long walls may need additional expansion gaps - allow 2mm per metre length of wall. This is on top of the 3mm expansion gap needed between each sheathing panel.

Breather membrane

  • To protect the structure of the building, use a suitable breather membrane installed on the external face of OSB wall sheathing in combination with a vapour control layer on the behind the plasterboard.
  • The membrane is usually installed in the factory but always check, the membrane should be overlapped at joints.

Wall ties

  • Use approved fixings to nail them through the wall sheathing into the supporting studwork that sits behind.
  • Thermal conductivity
  • 0.13 W/m.K for a mean density of 650 kg/m3 as set out in EN 13986
  • Water vapour ???????permeability'
  • OSB: Mean density:650 Kg/m3; Vapour Resistance factor: 30 Wet cup ????: 50Dry cup ????


  • Meets EN 300 and approved by the British Board of Agr????ment and the Irish Agr????ment board.
  • OSB/3 is suitable for humid conditions (as defined in terms of Service Class 2 of BS EN 1995-1-1:2004+A1:2008 for load bearing boards)
  • All UK and Irish OSB products conform with the Construction Products Directive (CPD) for structural use (attestation level 2+) via the CE mark
  • Manufactured by companies in the UK and Ireland that have been certificated to EN ISO9001:2000, the internationally recognised quality management system

If you'd like any more information, ask to see our KOMO/ETA/ VTT/Byggforsk.