The answer to 'cost to replace roof installation in Illinois' is that the cost can vary widely depending on several factors, but typically ranges from $10,000 to $30,000 for a full roof replacement. The exact cost will depend on the size of your roof, the type of roofing material used, the complexity of the job, and your location within Illinois.
Factors that can influence the cost include the roofing material (asphalt shingles, metal, tile, etc.), the pitch and slope of your roof, any necessary repairs to the underlying structure, and the labor rates in your local area. Additionally, the time of year and demand for roofing services can also impact pricing.