Size, Length, and Spacing of Joists

The selection of the size, length, and spacing of the joists will in­volve one of the following:

1. Given the total load on the decking, the spacing of the joists, and the size and grade of the joists, determine the maximum span for the joists.

2. Given the total load of the decking, the size and grade of the joists, determine the maximum spacing of the joists.

3. Given the total load on the decking, and the size and the span of the decking, determine the minimum size joists required.

For practical purposes, the selected span is rounded down to the next lower integer or modular value.