I think I purchased too much. By the looks of it I have about R-60 up there now. I would show a picture but it just insulation. All in all, it took about 3 hours. That included adding the deck boards to walk on. I really believe that I only had maybe R-30 before. It just did not look very deep. I understand that blown in insulation settles but it looked less than 12″ thick. With this additional fluff, I hope to reduce my gas usage this winter by 10%. The total cost on the insulation was $175. A 10% reduction in gas usage would be about $100. This will payback in less than two years. Since this will also help reduce the temperature difference between the upstairs and downstairs of my two story house I think that alone has made it worth it.