The answer to 'roof decking installation cost in Chicago' is that the cost can vary significantly depending on several factors, but generally falls within a range of $3 to $8 per square foot for materials and labor. The specific cost will depend on the size of your roof, the type of decking material used (plywood, OSB, etc.), the complexity of the installation, and any unique site conditions.
It's important to get quotes from multiple local roofing contractors to compare prices and find the best value for your project. They can assess your specific needs and provide a detailed estimate. Be wary of any unusually low bids, as they may indicate substandard workmanship or materials.