Floor Joist Are Usually What Size In Residential Construction

Types of floor joists the three main types of floor joists used in home construction are solid lumber i joists and open web floor trusses.

Floor joist are usually what size in residential construction.

Joists must exhibit the strength to support the anticipated load over a long period of time. You should also check your local building codes before starting construction and consult a structural engineer in unusual or extreme situations. Considering the cross section of a typical joist the overall depth of the joist is critical in establishing a safe and stable floor or ceiling system. In many countries the fabrication and installation of all framing members including joists must meet building code standards.

Ceiling joists are usually 2 by 6s or sometimes 2 by 4s if it is an older home. This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction. Putting all these factors together gives the minimum size joists needed for various types of wood grades of lumber sizes of boards spacing of joists and the load that will be placed on the floor. Floor joists are typically 2 by 8s 2 by 10s or 2 by 12s.

Some newer homes have manufactured i beam shaped joists. While joists can be made from many materials those used for residential construction are usually solid or engineered wood. Joist span and spacing is set by your local building code.