Timber Frame Floor Joist Size

Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors.

Timber frame floor joist size.

The joists can be longer or shorter as required by space and size and are typically spaced at either 450mm or 600mm apart. True floor joist span calculations can only be made by a structural engineer or contractor. These tables can help calculate whether floor joists are strong enough to support themselves and the load they carry without the help of any walls underneath. The thickness of flooring joists themselves will be determined by what s going on top of them.

Joists that sit below end matched joints must be at least 35mm thick. They span across the narrow dimension of the house and rest on the exterior walls. 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. A few of the most common factors that affect joist span include.

Solid timber joist sizes are provided in the bs 8103 3 span tables. These elements will greatly affect how far you can span your joists. Maximum span of 2x12 floor joist the most important design choices to consider when building a home are the species and grade of wood that is being used as well as joist size and spacing. Timber floor joists shall be adequate for the spans and loads and be correctly installed.

Where the tables do not apply or where there are concentrated loads floor joists should be designed by an engineer in accordance with technical requirement r5.