Make sure that you have enough protection from the rain before you start installing any insulation insite the building. Sometimes the scheduling of this is not coordinated very well and your insulator may start installing the insulation as soon as he sees the building is covered. But it is not enough just to cover it. The roofing or at least its underlayment must be providing enough protection from the rain during construction. Otherwise your insulation will get wet and it will cause mold problems later.