New treated 3″ x 1″ timber 3.6m.
Dimensions: 3″ x 1″. Tanalised timber 3.6m 75mm x 25mm. Rough sawn C24 treated. C24 timber is roughly 50% stronger than C16 timber, so is better suited to longer spans or heavier loads, so a C16 timber joist will not be able to bear the same load weight as a C24 timber joist.