The following table gives details of allowable spans and spacing between joists for the most common timber sizes used in floor construction.
Timber upper floor construction details.
You can then fit a thin plywood layer over the top to regulate your final floor finish.
A neat alternative with a timber joisted floor is to put 50mm timber battens on top of your floor deck at 400mm centres lay your underfloor heating pipes between the battens clip them to the deck and then cover with a lean mix screed.
Single joist timber floor is the easiest kind used for residential buildings whereas spans are short or moderate about 4 m and loads are comparatively lighter.
Hollow floors also known as suspended or timber floors are simply timber joists suspended across and supported by load bearing walls under the floor.
6 4 10 construction of timber floors upper floors shall be constructed in a workmanlike manner and provide satisfactory performance.
The ends of these timber joists are built into or suspended by joist hangers from the external walls of the property.
All the figures are based on normal domestic floor loadings where the floor construction is typically 18 25mm floor boards sheets with up to 12 5mm thick plasterboard and skim underneath.
These are basically timber rsjs rolled steel joists with an i shaped cross section comprising top and bottom flanges made of softwood or lvt laminated veneer timber bonded to a tall vertical web of osb oriented strand board or a similar engineered board.
The floor consists of wooden joists spaced 30 to 40 cm apart and supported on end walls over that timber boarding or planking is fixed.