Floor Joist Are Usually What Size In 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 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. Joists must exhibit the strength to support the anticipated load over a long period of time. Some newer homes have manufactured i beam shaped joists. A floor s framework is made up mostly of wooden joists that run parallel to one another at regular intervals.

Ceiling joists are usually 2 by 6s or sometimes 2 by 4s if it is an older home. When building a house or even a deck it is important to confirm you have the correct joist sizes spans and spacing before you get started. While joists can be made from many materials those used for residential construction are usually solid or engineered wood. 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.

In many countries the fabrication and installation of all framing members including joists must meet building code standards. Joist span and spacing is set by your local building code. 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.