What Is a Floor Joist?
The joists run perpendicular to the beams for support.
Here are the key components of a floor frame:
What Is a Floor Joist Span?
The Spruce / Michela Buttignol
Builders have the challenge of choosing joists that are appropriate to the load they carry while maximizing space.
Floor loads are described using two measurements: dead load and live load.
Dead load for residential construction is generally considered to be about 10 pounds per square foot.
What Is a Live Load?
An inaccessible attic space, on the other hand, might have a live load of only 20 psf.
Types of Floor Joists
There are three types of floor joists.
The differences are typically cost, lifespan, and complexity of installation.
Local building codes should always be consulted since unusual situations may call for different span recommendations.
True floor joist span calculations can only be made by a structural engineer or contractor.
A common choice for construction framing is 2-grade lumber.
Avoid using 3- or 4-grade lumber for structural framing applications.
Tip
If you are hand-picking boards, examine them for knots and other flaws.
Flaws in a board can make the board unusable as a joist board.
The width is considerably more important than the thickness of a board.
Floor joists that are properly installed can last more than 100 years.
The ends of the floor joists sit on the sill plate.
The center of the joists will sit on the beam.
The beam is held up by several support columns.
Floor joists are smaller horizontal pieces of wood that are placed in between beams to help evenly distribute weight.
I-Joists.The Engineered Wood Association.
University of Tennessee Agricultural Extension Service.
How Much Does It Cost to Replace Damaged or Rotting Floor Joists?HomeAdvisor.
