Final answer:
The ratio of backspan to cantilever floor joists shall not be less than 2 to 1.
Step-by-step explanation:
The ratio of backspan to cantilever floor joists shall not be less than 2 to 1 when supporting light frame exterior bearing walls and roof only. This means that for every 2 units of backspan, there should be at least 1 unit of cantilever floor joists.