Joist span and spacing is set by your local building code.
Standard floor joist spacing uk.
In many circumstances 16 inches would be your standard spacing for shed floor joist but this is just a rough guideline.
This spacing provides enough support for common usage such as the placement of furniture and foot traffic.
See the image below for an example of joists spaced 16 on center 16 o c.
You should check with your local building department for construction requirements in your area.
For upper floors with a 22mm thick chipboard decking and 12 5mm plasterboard ceiling a dead load of between 0 25kn m 2 and 0 5kn m 2 may be assumed.
As with the joist size the building code for your structure will stipulate the proper spacing between floor joists.
The code itself is determined by the engineering requirements of a particular building.
If a floor needs to support more than common items you may choose to reinforce the floor by spacing joists closer together.
While most residential construction uses 2x8 joists with 16 inch spacing there are many other factors you need to consider when determining the proper joist span length.
The floor joist span tables are based on the loadings given in the amended version of bs 6399 1 which is an imposed load of either a uniformly distributed load of 1 5 kn m or a concentrated load of 1 4 kn.
In many home constructions joists sit 16 inches apart beneath the floor.
The section sizes of the floor joists given in tables 1 and 2 should be regularised or be als or cls to enable floors and ceilings to be level.
Normally floor joists are spaced 16 inches apart on center.
Looking at this table you will see there is a choice in the size of floor joist 2 x 6 2 x 8 2 x 10 or 2 x 12 and there is a choice in the joist spacing 12 16 or 14.
Two options that arise could be your wider 24 and your narrower 12 options for spacing.
Builders can adjust their choice of lumber size and spacing depending on circumstances.
The floor joist spacing is the distance between the centers of any two installed joists.
Joists are to have minimum end bearing of 40mm.