Final answer:
Fasteners should be spaced every 6 inches when installing OSB subfloor to ensure it's securely attached to the wood joists.
Step-by-step explanation:
When installing OSB subfloor, the fasteners should penetrate the wood joist every 6". This spacing ensures that the subfloor is securely fixed to the joists and can support the expected loads. It's important to follow the correct fastener spacing to maintain the structural integrity of the flooring system. Always refer to local building codes and manufacturer guidelines for the specifics as there may be variations depending on the application and the product used.