Timber Floor Joist Sizes
Common species used in house framing include.
Timber floor joist sizes. Joist sizes the wood boards used as floor joists generally range in size from no smaller than 2 by 4 inches to no larger than 2 by 12 inches. Two by 6 inches is a joist size frequently used in both indoor floors and as deck joists. Bci joists are specially constructed i joists with flanges made from strong versa lam laminated veneer lumber with oriented stranded board webs and approved waterproof structural adhesives providing outstanding strength and durability. 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.
Southern yellow pine and douglas fir have high bending strength. Western red cedar eastern white pine and ponderosa pine have low bending strength. Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors. Hemlock spruce and redwood have medium bending strength.
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.