What is The R-Value of Spray Foam?

Spray Foam has the highest R-Value (7 per inch) of any insulation product available today.  Also, unlike Fiber Insulations such as Fibrglass, Cellulose, and Rockwool, Weatherwise Foam has a “real world” R-Value which is not affected by external forces.  Studies by the US Department of Energy found that Fiber Insulations loose half of their R-Values when outside temperatures reach -28°C.  Similar tests found the same effect from wind, with Fiber Insulations loosing half of their R-Values when exposed to a 15 km/h wind.