For example, if you’re using southern yellow pine lumber for your joists, the allowable cantilever overhangwould be 3′ for 2-by-10 joists spaced 16″ apart and spanning 12′ total. A Joist Span calculator commonly identifies the maximum span and cantilever for dimensional lumber joists based on wood type, joist size, and spacing between joists. All you have to do is input the information, press calculate, and the maximum span is identified. Different types of wood, even within species, have different physical characteristics and strengths. Growing conditions also contribute to the variations making timber from one area more desirable for different projects. Learn more about the UltraShield® advantage, or find a NewTechWood distributor near youto get started. Along the foundation wall (by the ledger), this needs to be continuous over 1.8m metres (NZS 7.1.4.2)

Cedar has a natural wood preservative that protects from rot and insects. However, cedar will gray with age and requires cleaning and sealing or staining regularly. It provides a warm wood glow that many appreciate. It too comes in 2-by and 5/4 dimensions. NZS 3604 also outlines many other requirements on joists such as fastenings, please refer to this document for more information. A circular saw:Use a circular saw to cut lumber to meet your project dimensions, according to the recommend joist length and width. The joists may be cantilevered at each end beam or terminate flush with the end beams. Joists that cantilever allow for the use of longer joists than those that terminate at the outside face of the beam.Typically, going with 12-inch or 16-inch joist spacing is a safe bet for the project, but if you want to ensure the spacing is adequate for the project, use the following formula: The information and advice in this article is provided in good faith and is designed to give general information and guidance. Any reliance you place on such information is therefore strictly at your own risk. If in doubt we strongly recommend you seek professional assistance. Now that all joists are attached to their hangers, they should be self-supporting with the help of your support beams. To close the frame, you will install one final rim joist along the open-ended edge of the joists:

Wood treatment or joist tape:Be sure to apply wood treatment or joist tape to every cut end of lumber to prevent moisture damage and warping. If you'd rather fasten down your risers, you can first lay a concrete foundation and then fix them in place with ground anchors. Erecting and spacing beams to allow shorter spans means less expensive and more readily available timbers may be used. It is better to go shorter than to try and maximize span bridging for a more solid and secure platform. Joist size determines span and spacing, so select the grade and type of wood best suited for your needs and budget. Support beams:Once you have installed a ledger, you will add the remaining support posts and any applicable center beams before continuing to the joists. There are so many variables and potential for error when calculating from scratch, that unless you’re a Structural Engineer tasked with the job, it’s better to use another method. My preference is to use span and spacing values readily available in Code tables or calculators.C16 Timber: C16 is the most commonly used form of timber. It can be used in many different applications and is the most cost effective option. C16 timbers are kiln dried to minimise the amount of moisture in the wood. This grade of timber which is commonly used in internal construction such as floors, walls and roof joists is not only cost effective, it has the strength and other properties such as bending, compression and density which are required for construction. As strong, versatile and cost effective this grade of timber might be, it does have some defects, such as grain deviations which may affect the strength of the timber as well as some cosmetic defects such as sap stains and sometimes and an uneven surface. A pencil or piece of white chalk:You need a lumber pencil or piece of white chalk to mark your joint spacing on your ledger board before installation. These are fixed to joists using 100mm landscape screws. If possible, fix the newels so that two faces can be secured through two joists at 90' to each other. 8. Fitting Steps Your surface must be level. While minor irregularities can be dealt with, your terrain should otherwise be perfectly flat. Some formulas take the bending, compression, and breaking values for wet or dry wood that are based on predetermined values for different species to determine safe loads over specified distances. The formulas have been used to calculate the spans and spacing on different tables in the Building Codes, and are the values used by different calculator algorithms.

Once each hanger is installed evenly and nailed into place, you can begin attaching your joist boards: Some equations and algorithms will calculate the span and spacing for joists and numerous joist span tables for reference too. Although laying and installing joists is a straightforward process, there are several things to consider, especially regarding size and spacing. Getting board dimensions or spacing distance wrong can compromise the integrity of your structure, and might even violate some local building codes. Beam Configuration – Ledger to Beam, Free Standing (joists resting on beam), or Joist Hangers (joists attached to beam sides with hangers) A bubble level:If you’re working alone, a bubble level will help you measure straight lines when installing joist hangers.

Galvanized hanger nails:You need 1 1/2″ joist hanger nails. Joist hanger nails are hot-dipped and galvanized. Be sure you have enough nails on hand to fill each hole on every hanger. The 2018 IRC is a good place to start as is your local Code which may adjust values or loads for regional conditions. Joist Spans for #2-Grade Dimensional Lumber

If you are dealing with bare earth make sure you flatten out the ground in advance or lay down a fine concrete screed to create a level surface. A scrap piece of lumber:Cut a piece of wood from your pressure-treated joist lumber to use as a guide when placing your joist hangers. Make sure the scrap wood is in the same dimensions as your joists. Extra lateral support is required between the joists. In NZS304 clause 7.1.2.4, this can being either be: Tables and span calculators frequently provide joist dimensions, span, and spacing values based on a dead load of 10 pounds per square foot (PSF or psf) and a live-load of 40psf. The height off the ground, wind-load, snow-load, soil-load capacity, and potential seismic forces also factor into the span. Four very popular types of spindle are usually used the Square, Chamfered, Colonial and American and each of them can be installed using a universal hand/base rail shown here. The spindles are held in place simply by fixing the infill strips between each spindle in both the top and bottom rails.In the United States, ASTM D7032 Label is the standard. In short, everything designed in a lab must be tested in a lab to know its strengths and properties. Use your chalk line reel to mark a straight line from each end joist — also called rim joists — tosee whether you need to further trim any joists to size. Remember, it is critical that the joists be the exact same length. If your joists require further trimming, use your circular saw, and remember to re-treat or tape the newly cut ends. Now, you need to use a pencil or white chalk to mark the face of the ledger board where your joists will be —exactly 16″ from center to center. If using a tape measure, be sure you securely place the tip of it against the outside of the ledger, so you get an accurate measurement.