Roof joists are horizontal structural associates that aid the roof deck and framework, transferring the load in to the walls below. Proper joist sizing and spacing ensure structural integrity. A new roof will typically Price between $4 and $forty for each sq. foot, based on the roofing product you use. https://www.prettypracticalhome.com/finding-the-best-roofing-contractors-in-illinois-your-ultimate-guide/