Sandwich panels are the ideal soluion for large installations that requires isothermal polyurethane installation
PUR / PIR foams may offer the most optimal solution . The closed structure of the plastic foams make it more resistant against water , however the contact of inorganic material such as Rockwool with water may cause serious reductions such as at %75 rates . At thermal  performance low thermal conductivity value means high thermal installation performance , so the required performance low can be easily achieved with the low insulation material thickness 


           Material             PIR sandwich panel     Rockwool                        

Thermal Conductivity      .22-.28 w/m.k        .34-.04w/m.k