In roofing, there are not a ton of surprises other than rotted wood and joists when we rip an old roof off. When the old layers of the roof are pealed away and disposed of, you will be able to see the original roof deck of your building. Depending on the condition of the roof, the deck will be in various conditions. The conditions will range from a healthy, solid roof, with no wood rot. Or you could have a roof that was letting in water causing the roof wood/joists to rot. When this occurs, we need to assess the scope to repair the damage so the roof will be as good as new.