Suspended ground floors

Also See:
4.3
6.4

5.2.8Transfer of loads: timber floors

Timber suspended ground floors, including the decking material, shall be designed and constructed to be suitable for their intended use. Issues to be taken into account include the:

  1. support of self-weight, dead and imposed loads and limited deflection
  2. safe transmission of loads to the supporting structure
  3. adverse effects of shrinkage and movement.

Support of self-weight, dead and imposed loads, and limited deflection

Structural timber grades and sizes should be adequate for the spans and imposed loads. Where trimming is necessary, adequately sized timbers should be used.

Safe transmission of loads to the supporting structure

Joist hangers should be suitable for:

  • the joist width and depth
  • the strength of masonry
  • the loading
  • providing adequate end bearings to joists.

Sleeper walls should adequately support the floor joists, and joists should be correctly supported at masonry separating walls.

Shrinkage and movement

Strutting should be provided where required to limit the twisting of joists.