Timber sizes for floor joists – Where can I obtain the timber sizes for floor joists and roofing members that are no longer directly contained in the current version of Approved Document A?

This information is contained in the guidance document published by the Timber Research and Development Association (TRADA) titled: – ‘Span tables for solid timber members in floors, ceilings and roofs (excluding trussed rafter roofs) for dwellings’, obtainable from:

TRADA Technology Ltd,
Chiltern House
Stocking Lane
Hughenden Valley
High Wycombe
Buckinghamshire
HP14 4ND

Or alternatively technical guidance is given in British Standard BS 8103 Part 3 2009 ‘Structural design of low-rise buildings – Code of practice for timber floors and roofs for housing’, obtainable from:

British Standards Institution
389 Chiswick High Road
London
W4 4AL