Divide the total span of the floor joists in inches by 360 to determine the maximum amount the floor can give in the middle under a live load of 40 lb sq.
Floor joist strength calculator.
There are six choices.
Also available for the android os.
Enter a specific joist size 2.
For example a joist made from doubled 2 x 6s can span a distance about 25 percent more than a single 2 x 6 but a 2 x 12 can span about 80 percent more than a 2 x 6 even.
Architects and engineers use these tables to determine the required size and spacing of joists as they design buildings but you can use them to work backwards and calculate the load capacity of an.
To calculate a specific value the tile council of north america tcna offers a standard formula.
It has been my experience to never use a beam smaller than a two ply 2 x 8.
Most lay outs are on 16 so the field is pre selected.
The strength of a given joist board is most dramatically affected by the board s top to bottom width.
These steel joints are needed to support the overall truss.
1 2 timber strength class and joist size automatically calculate sizes suitable for supporting the loads below or.
These small areas are usually door opening on the interior and people are trained that these areas are the strongest.
Select the on center spacing for the joists.
No matter what the specs say.
Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge.
The highest is a fully loaded floor 70 pounds per square foot.
Span calculator for wood joists and rafters also available for the android os.
Ft plus any long term deflection due to the weight of the floor.
For a given joist size and spacing the tables indicate the strength value called the fb value and stiffness called the e value of the joist.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
This calculator matches up with 90 of the applications in the 2012 international residential code book.
1 enter joist details.
Calculations to bs 5268 2 2002.
While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator.
Usually 400 450 or 600mm but any value can be used up to 610mm max.
Domestic floor joist calculator.
The width is considerably more important than the thickness of a board.
The more complex the truss framework is the greater quantity of these joints will be required.
This is how far apart they will be.
