Builders generally use pre calculated tables to tell them appropriate joist spans for each lumber species size and spacing.
Ground floor joist support.
Floor joists especially on the first floor must be durable enough and properly spaced in order to function effectively.
The weight of the building materials joists subfloor flooring and ceiling is known as the dead load and is commonly rated at 10 pounds per square foot.
The amount of weight on the floor is also an important factor in determining joist size and span length.
While they do not support the full weight of the home or other structure joists are instrumental in ensuring that the building is soundly framed.
A joist support is the horizontal beam that supports the floor joists.
Joist span refers to the measurement covered by the joist between supporting structures such as beams or foundation walls.
A floor joist span is the length a floor joist goes across a room.
In some cases additional joist supports will have to be installed before there can be extra heavy objects on the floor.
Floor joists spaced on regular intervals span the areas between supports such as walls foundations girders and beams.
Joist blocking blocking provides the floor joists with lateral support and it provides a way to transfer shear and vertical loads from the walls above to the foundation below.